Answer:
d apple's are the best fruit
Light with an intensity of 1 kW/m2 falls normally on a surface with an area of 1 cm2 and is completely absorbed. The force of the radiation on the surface is
Answer:
The force of the radiation on the surface is 3.33 X 10⁻¹⁰ N
Explanation:
Given;
intensity of light, I = 1 kw/m²
area of the surface, A = 1 cm² = 1 x 10⁻⁴ m²
Power of the incident light, P = I x A
Power of the incident light, P = (1 kw/m²) x (1 x 10⁻⁴ m²)
Power of the incident light, P = 1 x 10⁻⁴ kW = 0.1 W
Power of the incident light is given by;
P = Fv
where;
F is the force of the radiation on the surface
v is the speed of light = 3 x 10⁸ m/s
F = P/ v
F = (0.1) / (3 x 10⁸)
F = 3.33 X 10⁻¹⁰ N
Therefore, the force of the radiation on the surface is 3.33 X 10⁻¹⁰ N
If Matthew was traveling into space from Earth, which of these would he be able to reach first? A) Sun B) Venus C) Alpha centauri D) not enough information given
C.) Alpha Centauri
Explanation:
Due to it being the closest planetary system to earth.
About 4.367 light years away.
Answer: not enough information given
Explanation:
An ideal spring hangs from the ceiling. A 1.95 kg mass is hung from the spring, stretching the spring a distance d=0.0865 m from its original length when it reaches equilibrium. The mass is then lifted up a distance L=0.0325 m from the equilibrium position and released. What is the kinetic energy of the mass at the instant it passes back through the equilibrium position?
Answer:
kinetic energy = 0.1168 J
Explanation:
From Hooke's law, we know that ;
F = kx
k = F/x
We are given ;
Mass; m = 1.95 kg
Spring stretch; d = x = 0.0865
So, Force = mg = 1.95 × 9.81
k = 1.95 × 9.81/0.0865 = 221.15 N/m
Now, initial energy is;
E1 = mgL + ½k(x - L)²
Also, final energy; E2 = ½kx² + ½mv²
From conservation of energy, E1 = E2
Thus;
mgL + ½k(x - L)² = ½kx² + ½mv²
Making the kinetic energy ½mv² the subject, we have;
½mv² = mgL + ½k(x - L)² - ½kx²
We are given L=0.0325 m
Plugging other relevant values, we have ;
½mv² = (1.95 × 9.81 × 0.0325) + (½ × 221.15(0.0865 - 0.0325)² - ½(221.15 × 0.0865²)
½mv² = 0.62170875 + 0.3224367 - 0.82734979375
½mv² = 0.1168 J
An electron and a proton have their masses in the ratio 1:1840. What will be the ratio of their kinetic energy if they have equal momentum?
Answer:
1840:1
Explanation:
If m is the mass of the electron, and 1840m is the mass of the proton, then:
p₁ = p₂
m₁v₁ = m₂v₂
m v₁ = 1840m v₂
v₁ = 1840 v₂
The kinetic energy of the electron is:
KE₁ = ½ m₁ v₁²
KE₁ = ½ m (1840 v)²
KE₁ = 1692800 mv²
The kinetic energy of the proton is:
KE₂ = ½ m₂ v₂²
KE₂ = ½ (1840m) v₂²
KE₂ = 920 mv²
The ratio of the kinetic energies is:
KE₁ / KE₂
(1692800 mv²) / (920 mv²)
1840:1
What is the direction of the magnetic force on the current in each of the six cases?
Answer:
is the equation for magnetic force on a length l of wire carrying a current I in a uniform magnetic field B, as shown in Figure 2. If we divide both sides of this expression by l, we find that the magnetic force per unit length of wire in a uniform field is F l=IBsinθ.
Explanation:
The atomic mass number of copper is A=64. Assume that atoms in solid copper form a cubic crystal lattice. To envision this, imagine that you place atoms at the centers of tiny sugar cubes, then stack the little sugar cubes to form a big cube. If you dissolve the sugar, the atoms left behind are in a cubic crystal lattice. What is the smallest distance between two copper atoms?
Answer:
0.228 nm
Explanation:
Atomic mass number of copper = 64
but an atomic mass unit = 1.66 x 10^-27 kg
therefore, the mass of the copper atom m = 64 x 1.66 x 10^-27 kg = 1.06 x 10^-25 kg
The number of atoms in this mass n = ρ/m
where ρ is the density of copper = 8.96 x 10^3 kg/m^3
==> n = (8.96 x 10^3)/(1.06 x 10^-25) = 8.45 x 10^28 atoms/m^3
We know that the volume occupied by this amount of atoms n = [tex]a^{3}[/tex]
where a is the lattice constant
equating, we have
8.45 x 10^28 = [tex]a^{3}[/tex]
a = 4.389 x 10^9
we also know that
d = 1/a
where d is the smallest distance between the two copper atom.
d = 1/(4.389 x 10^9) = 2.28 x 10^-10 m
==> 0.228 nm
Light from a helium-neon laser (λ = 633 nm) is used to illuminate two narrow slits. The interference pattern is observed on a screen 2.5 m behind the slits. Eleven bright fringes are seen, spanning a distance of 54 mm. What is the spacing (in mm) between the slits?
Answer:
The value is [tex]d = 0.000293 \ m[/tex]
Explanation:
From the question we are told that
The wavelength is [tex]\lambda = 633 \ nm = 633 *10^{-9} \ m[/tex]
The distance of the screen is [tex]D = 2.5 \ m[/tex]
The order of the bright fringes is [tex]n = 10[/tex] (10 fringe + central maximum = eleven bright fringes )
The distance between the fringe is [tex]y = 54 \ mm = 0.054 \ m[/tex]
Generally the condition for constructive interference is
[tex]d sin \theta = n * \lambda[/tex]
=> [tex]d = \frac{n * \lambda}{sin \theta}[/tex]
Now from the SOHCAHTOA rule the angle [tex]sin \theta[/tex] is mathematically represented as
[tex]sin (\theta) = \frac{y}{D}[/tex]
So
[tex]d = \frac{n * \lambda}{\frac{y}{D} }[/tex]
=> [tex]d = \frac{10 * 633 *10^{-9}}{\frac{0.054}{ 2.5} }[/tex]
=> [tex]d = 0.000293 \ m[/tex]
A teacher performing a demonstration finds that a piece of cork displaces 44.5ml of water. The piece of cork has a mass of 11.1g. What is density of the cork
Explanation:
Density = mass / volume
ρ = 11.1 g / 44.5 mL
ρ = 0.249 g/mL
An oil layer that is 5.0 cm thick is spread smoothly and evenly over the surface of water on a windless day. What is the angle of refraction in the wa
Answer:
32.1
Explanation:
NOTE: You did not state the angle of incidence, and thus, I will be using 45° as my angle of incidence, all you need to do is replace it with your own value if it's different.
To solve this question, we are going to be using Snell's Law.
Snell's law describes the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass, or air.
Snell's law is mathematically given as
sin(A1)/sin(A2) = n2/n1, where
n1 = incidence index
n2 = refracted index
A1 = incidence angle
A2 = refracted angle
The refraction index of oil is 1.15, and that of water is 1.33, so
if we take oil first,
sin A2 = (n1.sinA1)/n2
sin A2 = (1 * sin 45)/1.15
sin A2 = 0.7071/1.15
sin A2 = 0.6149
A2 = sin^-1 0.6149
A2 = 37.9°
Then
sin A3 = (1.15 * sin 37.9) / 1.33
sin A3 = (0.6149 * 1.15) / 1.33
sin A3 = 0.7071 / 1.33
sin A3 = 0.5317
A3 = sin^-1 0.5317
A3 = 32.1
Select the correct answer from each drop-down menu.
What forms of energy are involved when snow on a mountain breaks loose, resulting in an avalanche?
During an avalanche, the
energy of the snow on the mountain is converted into
energy as the snow cascades down.
Answer:
Gravitational potential energy is converted into kinetic energy
Explanation:
During an avalanche, the gravitational potential
energy of the snow on the mountain is converted into
kinetic energy as the snow cascades down.
The potential energy stored by the snow collected high in the mountain under the gravitational field created by our Earth, breaks loose and as it comes down acquiring velocity, it is converted into kinetic energy due to its accelerated motion
A race car is on a track has a velocity of 200 m/s. 15 seconds later the driver notices that he is going 350 m/s. What is his acceleration?
Answer:
initial velocity (u) = 200m/s
final velocity (v) = 350 m/s
time (t) = 15s
acceleration (a) = ?
NOW,
a=v-u/t
a= 350-200/15
a= 50/15
a= 3.3333
Explanation:
it's too easy just u need to understand the question . and go according to it's content .
main thing to memorize is it's simple formula.
I HAVE SOLVE THIS QNA. IN VERY
SIMPLE AND UNDERSTANDABLE FORM.
I høpë u hađ uņdērstøöď ťhìs şølutîóñ
:verý ×wəłł.
A sealed tank containing seawater to a height of 10.5 mm also contains air above the water at a gauge pressure of 2.95 atmatm. Water flows out from the bottom through a small hole. How fast is this water moving?
Answer:
The water is flowing at the rate of 28.04 m/s.
Explanation:
Given;
Height of sea water, z₁ = 10.5 m
gauge pressure, [tex]P_{gauge \ pressure}[/tex] = 2.95 atm
Atmospheric pressure, [tex]P_{atm}[/tex] = 101325 Pa
To determine the speed of the water, apply Bernoulli's equation;
[tex]P_1 + \rho gz_1 + \frac{1}{2}\rho v_1^2 = P_2 + \rho gz_2 + \frac{1}{2}\rho v_2^2[/tex]
where;
P₁ = [tex]P_{gauge \ pressure} + P_{atm \ pressure}[/tex]
P₂ = [tex]P_{atm}[/tex]
v₁ = 0
z₂ = 0
Substitute in these values and the Bernoulli's equation will reduce to;
[tex]P_1 + \rho gz_1 + \frac{1}{2}\rho v_1^2 = P_2 + \rho gz_2 + \frac{1}{2}\rho v_2^2\\\\P_1 + \rho gz_1 + \frac{1}{2}\rho (0)^2 = P_2 + \rho g(0) + \frac{1}{2}\rho v_2^2\\\\P_1 + \rho gz_1 = P_2 + \frac{1}{2}\rho v_2^2\\\\P_{gauge} + P_{atm} + \rho gz_1 = P_{atm} + \frac{1}{2}\rho v_2^2\\\\P_{gauge} + \rho gz_1 = \frac{1}{2}\rho v_2^2\\\\v_2^2 = \frac{2(P_{gauge} + \rho gz_1)}{\rho} \\\\v_2 = \sqrt{ \frac{2(P_{gauge} + \rho gz_1)}{\rho} }[/tex]
where;
[tex]\rho[/tex] is the density of seawater = 1030 kg/m³
[tex]v_2 = \sqrt{ \frac{2(2.95*101325 \ + \ 1030*9.8*10.5 )}{1030} }\\\\v_2 = 28.04 \ m/s[/tex]
Therefore, the water is flowing at the rate of 28.04 m/s.
Answer:
C. effusion because there is a movement of a gas through a small opening into a larger volume
Explanation:
Edge2020
Have a great day y'all :)
Statement I: At the same temperature lighter gas molecules have a higher average velocity than heavier gas molecules.
Statement II: At the same temperature lighter gas molecules have a higher average kinetic energy than heavier gas molecules.
a) Statement 1 and statement 2 are correct and statement 2 is the correct explanation of statement 1
b) Both the statement 1 and statement 2 are correct and statement 2 is not the correct explanation of statement 1
c) Statement 1 is correct but statement 2 is not correct
d) Statement 1 is not correct but statement 2 is correct
e) Both the statement 1 and statement 2 is not correct
Answer:
Statement 1 and statement 2 are correct and statement 2 is the correct explanation of statement 1
Explanation:
Both the velocity and kinetic energy of a gas molecule depends on its relative molecular mass according to Graham's law of diffusion in gases. Hence, the greater the relative molecular mass of the gas, the lesser its average velocity and kinetic energy.
Hence we can see that statement 2 vividly explains the postulation of statement 1 and makes the points more easily comprehensible.
Trial 1: Get a textbook and put a sheet of paper on top of it. Fold the paper as needed to keep the paper from sticking over the edge of the book.Hold the textbook with the paper on top, horizontally about waist high.Drop the book and paper so that they hit the floor flat. Record your observations.Trial 2: With the book in one hand and the paper in the other, drop the book and paper simultaneously from the same height. Record your observations.
Answer:
1) the two objects reach the floor at the same time.
2)the book reaches the floor much earlier than the foil
In conclusion, the difference in motion between the two systems subjected to the same acceleration depends on the weight of the body and friction force, when the body has less weight, the friction of the air affects it more
Explanation:
This interesting experiment has the following results
1) first case. Sheet on top of book
In this case the two objects reach the floor at the same time.
This shows that the acceleration in the two objects is the same and we call it the acceleration of gravity.
The speed of the body increases as it goes down linearly.
This occurs because the book that receives air resistance is much heavier, so the resistance has almost no effect on its movement, the sheet does not have the air resistance because it goes down next to the book.
2) second case. Book and sheet next to each other.
In this case the book reaches the floor much earlier than the foil.
This is because the resisting force of the air has almost no effect on the book and its movement is little affected by this force.
In the case of the blade, it has very little weight, therefore as its speed increases, the resistance force of the air rapidly equals the weight of the blade.
W_sheet - fr = 0
so after this, since the acceleration is zero, it goes down at constant speed, this speed is called the terminal velocity.
In conclusion, the difference in motion between the two systems subjected to the same acceleration depends on the weight of the body and friction force, when the body has less weight, the friction of the air affects it more.
Please help and thank you :)
Answer:
20 m/s.
Explanation:
Data obtained from the question include the following:
Initial position (d1) = 20 m
Final position (d2) = 60 m
Initial time (t1) = 1 sec
Final time (t2) = 3 secs
Velocity (v) =?
Next, we shall determine the change in position (Δd). This can be obtained as follow:
Initial position (d1) = 20 m
Final position (d2) = 60 m
Change in position (Δd) =?
Change in position (Δd) = d2 – d1
Change in position (Δd) = 60 – 20
Change in position (Δd) = 40 m
Next, we shall determine the change in time (Δt). This can be obtained as follow:
Initial time (t1) = 1 sec
Final time (t2) = 3 secs
Change in time (Δt) =?
Change in time (Δt) = t2 – t1
Change in time (Δt) = 3 – 1
Change in time (Δt) = 2 secs.
Finally, we shall determine the velocity of the object as follow:
Change in position (Δd) = 40 m
Change in time (Δt) = 2 secs.
Velocity (v) =?
Velocity (v) = Change in position (Δd) /Change in time (Δt)
v = Δd/Δt
v = 40/2
v = 20 m/s
Therefore, the velocity of the object between 1 and 3 secs is 20 m/s
Roy took 5 hours to complete a journey. For the first 2 hours,
he travelled at an average speed of 65 km/h. For the rest of
the journey, he travelled at an average speed of 78 km/h. What
was the total distance of the journey?
Answer:
use the distance formula d=v*t
d= distance
v = velocity
t = time = t1 + t2 = 2h +3h = 5 hours (total time given)
At 65 km/h distance (d1) answer:
d1 = (65 km/h)*( 2h) = 130 km
Total Distance:
so d1 + d2 = Dtotal
Dtotal = 130 km + (78 km/h)*3 = 130 km + 234 km = 364 km
When an external magnetic field is applied, what happens to the protons in a sample?
A) All protons align with the field.
B) All protons align opposite to the field.
C) Some protons align with the field and some align opposite to it.
D) All protons assume a random orientation.
Answer:
Some protons align with the field and some align opposite to it.
Explanation:
Majority align to the field because these protons tend to act like small magnets under the effect of this external field
On account of external magnetic field, the protons will align with the magnetic field. Hence, option (a) is correct.
The given problem is based on the concept of magnetic field. The region where the magnetic force is experienced is known as magnetic field. Generally, the protons are the charged entities carrying the positive polarity and are one of the major constituents of modern atomic structure.
The origin of magnetic field occurs due to charged particles present in a specific space. And the magnetic field is due to the flowing of liquid metal in the outer core of the planet generates electric currents.In the condition when an external field is applied, the majority of protons align to the field because these protons tend to act like small magnets under the effect of this external field.Thus, we can conclude that on account of external magnetic field, the protons will align with the field.
Learn more about the magnetic field here:
https://brainly.com/question/14848188
A 68.5 kg astronaut is doing a repair in space on the orbiting space station. He throws a 2.25 kg tool with a speed of 3.20 m / s relative to the space station. With what speed and direction will the astronaut begin to move?
Explanation:
Momentum is conserved.
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
Initially, both the astronaut and the tool are at rest, so u₁ = u₂ = 0 m/s.
After throwing the tool, the tool has a velocity of v₂ = 3.20 m/s.
(68.5 kg) (0 m/s) + (2.25 kg) (0 m/s) = (68.5 kg) v + (2.25 kg) (3.20 m/s)
0 = (68.5 kg) v + 7.2 kg m/s
v = -0.105 m/s
The astronaut moves at a speed of 0.105 m/s in the opposite direction.
The speed and the direction of the astronaut is 0.105 m/s in opposite direction to the motion of the tool.
Note: The momentum of the astronaut is equal and opposite to the momentum of the tool
To calculate the speed and the direction of the astronaut, we use the formula below.
Formula:
MV = -mv.............. Equation 1Where:
M = mass of the astronautV = speed of the astronautm = mass of the toolv = speed of the tool.make V the subject of the equation
V = mv/M................. Equation 2From the question,
Given:
m = 2.25 kgM = 68.5 kgv = 3.2 m/sSubstitute these values into equation 2
V = (2.25×3.2)/68.5V = 0.105 m/s in opposite direction to the speed of the tool.Hence, The speed and the direction of the astronaut is 0.105 m/s in opposite direction to the motion of the tool.
Learn more about speed here: https://brainly.com/question/13943409
A nucleus of carbon 14 has 6 protons and 8 neutrons. The atomic number and mass number of carbon 14 are, respectively,
a) 6 and 8
b) 6 and 14
c) 8 and 14
d) 14 and 20
e) 14 and 22
Answer:
6 and 14 respectively
Explanation:
proton number = atomic number
mass number = proton number + neutron number
since
p.n = a.n = 6m.n = p.n + n.nm.n = 6 + 8 = 14m.n = 14g If the momentum of an electron doubles, by what factor would its de Broglie wavelength be multiplied
Explanation:
The de broglie wavelength is given by :
[tex]\lambda=\dfrac{h}{p}[/tex]
Here,
h is Planck's constant
p is momentum
Momentum and De-Broglie wavelength has inverse relationship. If momentum of an electron double, its wavelength gets half.
What is the mass of a rock lifted 2 meters off the ground that has 196 J of potential energy?
Answer:
10kg
Explanation:
Let PE=potential energy
PE=196J
g(gravitational force)=9.8m/s^2
h(change in height)=2m
m=?
PE=m*g*(change in h)
196=m*9.8*2
m=10kg
What properties do you think a spoon must have for it to be
useful as an eating tool? What additional properties must an edible spoon
have?
Answer:
eating instrument must be: HARDNESS, INERT, NOT TOXIC
eating tools: digested by the body
Explanation:
An eating instrument must be able to contain food, so it must have a good HARDNESS, besides it must be poorly absorbent of heat and the most important must be INERT, not react with food or be NOT TOXIC to humans.
Additionally, for a spoon to be edible, it must be able to be digested by the body, in general they are made with a starch base, so that the non-digestible parts of it have not been toxic to the body and can be eliminated from it.
There are numerous features of a spoon but these properties must an edible spoon
have
A spoon must be Sizable in nature to be use on the mouthA spoon must not contain an fatal substance as it will be used for eating A spoon Strong and not weather under pressure of heat A spoon should be Durable to stand the test of timeFor more information on this visit
https://brainly.com/question/13480859?referrer=searchResults
A particle has velocity v⃗1 v → 1 as it accelerates from 1 to 2. What is its velocity vector v⃗2 v → 2 as it moves away from point 2 on its way to point 3?
Answer:
The velocity of the particle will be downward.
Explanation:
Given that,
The velocity of a particle is v₁. It is accelerated from 1 to 2.
If it moves away from point 2 on its way then
We need to find the velocity of particle
According to figure,
A particle moves downward from 1 to 2 with the velocity v₁ and after that the particle moves downward from 2 to 3 with the velocity v₂.
Hence, The velocity of the particle will be downward.
A stretched string is observed to vibrate in three equal segments when driven by a 480-Hz oscillator. What is the fundamental frequency of vibration for this string
Answer:
160 Hz
Explanation:
Fundamental frequency, [tex]f_{0}[/tex], is the lowest frequency that can be obtained from the stretched string. While higher frequencies are termed harmonics or overtones.
Since the string has three equal segments, the frequency generated, [tex]f_{2}[/tex], is the second harmonic but third overtone.
From the relationship between [tex]f_{0}[/tex] and [tex]f_{2}[/tex], we have;
[tex]f_{2}[/tex] = 3[tex]f_{0}[/tex]
⇒ 480 = 3[tex]f_{0}[/tex]
[tex]f_{0}[/tex] = 160
The fundamental frequency of vibration for the string is 160 Hz.
If a mass on a spring is 16 kg and the spring constant is 4 N/m, what would be its period?
Explanation:
T = 2π√(m/k)
T = 2π√(16 kg / 4 N/m)
T = 4π s
T ≈ 12.6 s
Two long parallel wires are separated by 6.0 mm. The current in one of the wires is twice the other current. If the magnitude of the force on a 3.0-m length of one of the wires is equal to 8.0 μN, what is the greater of the two currents?
Answer:
Explanation:
Magnitude of force per unit length of wire on each of wires
= μ₀ x 2 i₁ x i₂ / 4π r where i₁ and i₂ are current in the two wires , r is distance between the two and μ₀ is permeability .
Putting the values ,
force per unit length = 10⁻⁷ x 2 x i x 2i / ( 6 x 10⁻³ )
= .67 i² x 10⁻⁴
force on 3 m length
= 3 x .67 x 10⁻⁴ i²
Given ,
8 x 10⁻⁶ = 3 x .67 x 10⁻⁴ i²
i² = 3.98 x 10⁻²
i = 1.995 x 10⁻¹
= .1995
= 0.2 A approx .
2 i = .4 A Ans .
The greater current is 0.4 A
Since the two long wires are parallel, the magnetic force, F on each wire is given by
F = μ₀I₁I₂L/2πd where μ₀ = permeability of free space = 4π × 10⁻⁷ H/m, I₁ = current in first wire, I₂ = current in second wire, L = length of section of wires = 3.0 m and d = separation distance of the wires = 6.0 mm = 6.0 × 10⁻³ m.
Given that F = 8.0 μN = 8.0 × 10⁻⁶ N and I₂ = 2I₁ (the current in one wire is twice the current in the other wire), we have
F = μ₀I₁I₂L/2πd
F = μ₀ 2I₁I₁L/2πd
F = μ₀I₁²L/πd
Since we require the current in the wire, we make I₁ subject of the formula.
So, I₁ = √(Fπd/μ₀L)
Substituting the values of the variables into the equation, we have
I₁ = √(Fπd/μ₀L)
I₁ = √[8.0 × 10⁻⁶ N × π × 6.0 × 10⁻³ m/(4π × 10⁻⁷ H/m × 3.0 m)]
I₁ = √[48.0π × 10⁻⁹ Nm/12π × 10⁻⁷ H]
I₁ = √[4 × 10⁻² Nm/H]
I₁ = 2 × 10⁻¹ A
I₁ = 0.2 A
Since I₂ is the greater current and I₂ = 2I₁,
I₂ = 2 × 0.2 A
I₂ = 0.4 A
So, the greater current is 0.4 A
Learn more about current between two parallel wires
https://brainly.com/question/13090698
6° with the horizontal) at a steady speed of 4.0 m/s. Assuming a total mass of 75 kg (bicycle and Kasek), what must be Kasek's power output to climb the same hill at the same speed?
Answer:
Power, P = 307.31 W
Explanation:
It is given that,
Kasek climb at an angle of 6° with the horizontal at a steady speed of 4.0 m/s.
The total mass of bicycle and Kasek is 75 kg
We need to find the Kasek's power output to climb the same hill at the same speed. The angle is made with the horizontal. It means that,
F = F sinθ
So,
Power output is given by :
[tex]P=mg\sin\theta\times v\\\\P=75\times 9.8\times \sin(6)\times 4\\\\P=307.31\ W[/tex]
So, Kasek's power output to climb the same hill is 307.31 W.
The greatest speed recorded by a baseball thrown by a pitcher was 162.3 km / h, obtained by Nolan Ryan in 1974. If the ball leaves the pitcher's hand with a horizontal speed of this magnitude, how much will the ball have fallen? by the time you have traveled 20 m horizontally?
Answer:
0.96 m
Explanation:
First, convert km/h to m/s.
162.3 km/h × (1000 m/km) × (1 hr / 3600 s) = 45.08 m/s
Now find the time it takes to move 20 m horizontally.
Δx = v₀ t + ½ at²
20 m = (45.08 m/s) t + ½ (0 m/s²) t²
t = 0.4436 s
Finally, find how far the ball falls in that time.
Δy = v₀ t + ½ at²
Δy = (0 m/s) (0.4436 s) + ½ (-9.8 m/s²) (0.4436 s)²
Δy = -0.96 m
The ball will have fallen 0.96 meters.
(b) A ball is thrown upward from the top of a 30 m tower with initial velocity 90 m/s at an angle
O = 20°
Find the time to reach the ground
(Smarks)
Find the magnitude and direction of the velocity at the moment of impact (5 marks)?
Answer:
7.14 s
93.2 m/s, 24.9° below the horizontal
Explanation:
Given in the y direction:
Δy = -30 m
v₀ = 90 m/s sin 20° ≈ 30.8 m/s
a = -9.8 m/s²
Find: t
Δy = v₀ t + ½ at²
-30 m = (30.8 m/s) t + ½ (-9.8 m/s²) t²
4.9t² − 30.8t − 30 = 0
t = [ 30.8 ± √((-30.8)² − 4(4.9)(-30)) ] / 2(4.9)
t = 7.14 s
Find: vᵧ
v² = v₀² + 2aΔy
vᵧ² = (30.8 m/s)² + 2 (-9.8 m/s²) (-30 m)
vᵧ = -39.2 m/s
The magnitude of the velocity is:
v² = vₓ² + vᵧ²
v² = (90 m/s cos 20°)² + (-39.2 m/s)²
v = 93.2 m/s
The direction of the velocity is:
tan θ = vᵧ / vₓ
tan θ = (-39.2 m/s) / (90 m/s cos 20°)
θ = -24.9°
Consider the following:
a) radio waves emitted by a weather radar system to detect raindrops and ice crystals in the atmosphere to study weather patterns;
b) microwaves used in communication satellite transmissions;
c) infrared waves that are perceived as heat when you turn on a burner on an electric stove;
d) the multicolor light in a rainbow;
e) the ultraviolet solar radiation that reaches the surface of the earth and causes unprotected skin to burn; and
f) X rays used in medicine for diagnostic imaging.
Answer:
They have different wavelengths.
They have different frequencies.
They propagate at different speeds through non-vacuum media depending on both their frequency and the material in which they travel.
Explanation:
The complete question is
Consider the following:
a) radio waves emitted by a weather radar system to detect raindrops and ice crystals in the atmosphere to study weather patterns;
b) microwaves used in communication satellite transmissions;
c) infrared waves that are perceived as heat when you turn on a burner on an electric stove;
d) the multicolor light in a rainbow;
e) the ultraviolet solar radiation that reaches the surface of the earth and causes unprotected skin to burn; and
f) X rays used in medicine for diagnostic imaging.
Which of the following statements correctly describe the various forms of EM radiation listed above?
check all that apply to the above
They have different wavelengths.
They have different frequencies.
They propagate at different speeds through a vacuum depending on their frequency.
They propagate at different speeds through non-vacuum media depending on both their frequency and the material in which they travel.
They require different media to propagate.
All the above phenomena are due the electromagnetic wave spectrum. Electromagnetic waves travel at a constant speed of 3 x 10^8 m/s in a vacuum. Within the spectrum, the different types of electromagnetic waves exists in different band range of frequencies and wavelengths unique to each of the waves, and the energy they carry. When these waves enter a non-vacuum medium, their speed change, depending on the nature of the material of the medium, and the frequency or the wavelength of the incoming wave.