Answer:
F = mg /μ
Explanation:
For this exercise we define a coordinate system with the horizontal x axis and the vertical y axis, let's write the equilibrium equations for each axis
X axis
F -N = 0
F = N
Y axisy
fr - W = 0
fr = W (2)
the force and touch have the expression
fr = μ N
we substitute
fr = μ F
we substitute in 2
μ F = m g
F = mg /μ
Should we use less energy because it is
harming the planet?
Answer:
Yes - si.
Explanation:
Answer:
yes we should use less energy
A balloon of diameter 20.0 cm is filled with helium gas at 30°C at 1.00 atm. How
many atoms of helium gas fill a balloon having a diameter of 20.0 cm at 30.0°C
at 1.00 atm?
Answer:
N = 3.54 * 10²³ atoms
Explanation:
The formula to apply here is the idea gas law;
PV = nRT where ;
P= pressure of the gas= 1.013 * 10⁵ Pa
V= volume of the gas = 4/3 * 3.14 *0.15³= 0.01414 m³
n= amount of a substance = ?
R= ideal gas constant= 8.314
T= temperature= 293 K
Applying the values to the formula;
PV = nRT
1.013 * 10⁵ * 0.01414 = n * 8.314*293
n= 1.013 * 10⁵ * 0.01414 / 8.314*293
n= 0.588 moles
1 mole = 6.022 * 10²⁷ atoms/ mole
0.588 moles = 0.588 * 6.022 * 10²⁷
N = 3.54 * 10²³ atoms
A truck with the mass of 8 ton travels at a velocity of 60km/h and collides
with a truck with a mass of 5 tons travelling in the same direction at 40km/h.
After the collision the two trucks move together.
Calculate the final common velocity if the TWO trucks in m/s after the
collision?
Answer:
52 km/h
Explanation:
When the two trucks move together after collision, the momentum of the system is conserved. The kinetic energy is not conserved. This is inelastic collision
The formula to apply here is :
m₁v₁ + m₂v₂ = {m₁+ m₂} *vf
Given that ;
m₁ = 8 ton ----convert to kg [ multiply by 907.185] =7258 kg
v₁ = 60 km/h
m₂ = 5 tons ------4536 kg
v₂ = 40 km/h
vf = final velocity
Using the values given;
m₁v₁ + m₂v₂ = {m₁+ m₂} *vf
8*60 + 5*40 = {8+5} * vf
480 + 200 = 13 * vf
680 = 13vf
680/13 = vf
52 km/h = vf
A 0.54 kg bullfrog is sitting at rest on a level log. How large is the normal force of the log on the bullfrog?
Answer:
5.3NExplanation:
Step one:
given data
mass of bullfrog= 0.54kg
Step two:
Required
The force F in Newton
From newton first law
F=mg
The acceleration due to gravity acting on the frog is 9.81m/s^2
hence
F=0.54*9.81
F=5.3N
The normal force is 5.3N
If Steve throws the football 50 meters in 3 seconds, what is the average speed of the football? Speed = distance / time Question 2 options: A. 16.67 m/s B. 26 m/s C. 5 m/s D. 48.9 m/s
Answer:
A. 16.67 m/s
Explanation:
Speed or velocity refers to the rate of change in distance over a change in time. That is;
Speed = Distance ÷ time
Where;
Speed is in metre/seconds
Distance is in metre
Time is in seconds.
In this question, Steve throws a football 50 meters in 3 seconds. The average speed can be calculated this:
S = D/t
Where; d = 50m, t = 3s
S = 50/3
S = 16.6666666
S = 16.67m/s
A penny was thrown downward at 2.4 m/s and falls under the influence of
gravity for 5 s. What is the final velocity of the penny?
Answer:
v = 51.4 m/s
Explanation:
Given that,
Initial velocity of a penny, u = 2.4 m/s
It fall under the influence of gravity for 5 s.
We need to find the final velocity of the penny. Let v is its final velocity. It can be calculated using first equation of motion as follows :
[tex]v=u+at[/tex]
a = g
[tex]v=2.4+9.8(5)\\\\=51.4\ m/s[/tex]
So, the final velocity of the penny is 51.4 m/s.
what is mass? what is mass ?
Answer:
Mass, in physics, quantitative measure of inertia, a fundamental property of all matter. ... It is, in effect, the resistance that a body of matter offers to a change in its speed or position upon the application of a force. The greater the mass of a body, the smaller the change produced by an applied force.
Explanation:
AnsA
Explanation:
The amount of matter in an object
A coin falling through a vacuum loses no energy to friction, and yet after it hits the ground it has lost all its potential and kinetic energy. Which statement best explains why the law of conservation of energy is still valid in this case
Answer:
Explanation:
When coin is at a height and rest, it only has potential energy( by the virtue of its position). While the coin is falling its potential energy changes into kinetic energy. This means that its potential energy is decreasing and kinetic energy increases. just before its hits the ground kinetic energy is maximum and potential energy becomes zero.
When it hits the ground all its kinetic energy is converted into heat.
The 4.00 kg block is attached to a vertical rod by means of two strings. When the system rotates about the axis of the rod, the strings are extended as shown in the (Figure 1) and the tension in the upper string is 76.0 N.
Find the number of revolutions per minute at which the lower cord just goes slack.
Answer:
Let theta be angle of upper string with rod.
This a 3-4-5 triangle where R is distance of block from rod. (.75 - 1 - 1.25)
Fc = m w^2 R where Fc the centripetal force and w the angular velocity
Fc = T sin theta = T * .75 / 1.25 = .6 T = 45.6 N
w^2 = 45.6 / (4 * .75)
w = 3.90 /sec
RPM = 3.90 / sec * 60 sec / min / (2 * pi) = 37.2 RPM (2 pi rad / rev)
The number of revolutions per minute at which the lower cord just goes slack is 45.36 RPM.
The given parameters;
mass of the block, m = 4 kgthe tension on the upper string, T₁ = 76 NThe following triangle can be formed from the given diagram;
|
| 1 m
|---------x--------(θ) 4.00 kg
The hypotenuse of this triangle = 1.25 m
The height of the triangle = 1 m
The base of the triangle is calculated as;
[tex]x^2 = 1.25^2 - 1^2\\\\x^2 = 0.5625\\\\x = \sqrt{0.5625} \\\\x = 0.75 \ m[/tex]
Resolving the vertical component of the force;
Tension at the upper = Tension at the lower string
[tex]T_1 sin(\theta) = T_2 sin(\theta) + mg\\\\76 \times \frac{1}{1.25} = T_2 \times \frac{1}{1.25} + (4\times 9.8)\\\\76 = T_2 + 39.2\\\\T_2 = 76 - 39.2\\\\T_2 = 36.8 \ N[/tex]
Resolving the horizontal component of the force;
[tex]T_1cos(\theta) + T_2cos(\theta) = F_c\\\\T_1cos(\theta) + T_2cos(\theta) = mr\omega^2 \\\\76\times \frac{0.75}{1.25} \ + \ 36.8\times \frac{0.75}{1.25}= 4\times 0.75\tmes (\frac{2\pi N}{60} )^2\\\\67.68 = 0.0329N^2\\\\N^2 = \frac{67.68}{0.0329} \\\\N^2 = 2057.14\\\\N = \sqrt{2057.14} \\\\N = 45.36 \ rpm[/tex]
Thus, the number of revolutions per minute at which the lower cord just goes slack is 45.36 RPM.
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The trunk of a elephant may extend up to 2.2 m. It acts much like an organ pipe only open at one end when the elephant blows air through it. 1) Calculate the fundamental frequency of the sound the elephant can create with its trunk.2) If the elephant blows even harder, the next harmonic may be sounded. What is the frequency of the first overtone?
Answer:
1) f = 38.63 Hz , 2) f = 115.9 Hz
Explanation:
The elephant's trunk can be approximated by a tube with a closed end, in pipes the closed ends correspond to nodes and the open ends to antinodes or bellies.
The expression for the wavelengths of this system is
4L = n λ
n = 1, 3, 5, 7 ...
also let's use the relationship between frequency and wavelength and wave speed
v = λ f
f = v / λ
f = v n / 4L
f = v / 4L n
1) the fundamental frequency occurs for n = 1
f = 340/4 2.2 1
f = 38.63 Hz
2) The first harmonic
n = 3
f = 340/4 2.2 3
f = 115.9 Hz
Please select the word from the list that best fits the definition The skeletons of tiny ocean animals grow together to form ______, structures that are found only in warm, clear ocean water.
Answer:
coral reef
Explanation:
Use the drop-down menus to complete each statement.
In the mitochondria small molecules combine with to produce and carbon dioxide.
This process releases a large amount of .
Answer:
oxygen, water , energy
Explanation:
i took the instruction where this is from
Answer:
oxygen/water/energy
Explanation:
edge2020
God Bless You<3
A car is traveling 60 km/h and accelerates at a rate of 4 m/s^2 how long does it take the car to get to 90 km/h? ( please show work)
Answer:
Vf = 90km/h
(90*1000)/3600 ==>
(90*10)36
Vf = 25m/s
, Vi = 60km/h
(60*1000)/3600
16.666m/s =>16.7m/s
, a = 4m/s^2
t = ?
Explanation:
Vf = Vi + at
25m/s = 16.7m/s +4m/s^2(t)
25m/s - 16.7m/s = 4m/s^2(t)
8.3m/s = 4m/s^2(t)
8.3m/s/4m/s^2 = t
2.075s = t => 2.1s
What were the three topographical climate factors we talked about?
Group of answer choices
B.Grasslands, Tundra, Mountains
C.Dry Arid, Grasslands, Tundra
D.Dry Arid, Coastal, Mountains
A.Coastal, Dry Arid, Grasslands
Answer:
Dry Arid, Coastal, Mountains
Explanation:
Took the text
A 5000 kg open train car is rolling on frictionless rails at 22 m/s when it starts pouring rain. A few minutes later, the car’s speed is 20 m/s. What mass of water has collected in the car?
Answer:
500 kg
Explanation:
It is given that,
The mass of a open train car, M = 5000 kg
Speed of open train car, V = 22 m/s
A few minutes later, the car’s speed is 20 m/s
We need to find the mass of water collected in the car. It is based on the conservation of momentum as follows :
initial momentum = final momentum
Let m is final mass
MV=mv
[tex]m=\dfrac{MV}{v}\\\\m=\dfrac{5000\times 22}{20}\\\\=5500\ kg[/tex]
Water collected = After mass of train - before mass of train
= 5500 - 5000
= 500 kg
So, 500 kg of water has collected in the car.
The mass of the water collected in the car due to the rain is 500 kg.
The given parameters;
mass of the car, m = 5000 kgvelocity of the car, u = 22 m/sfinal speed of the car, v = 20 m/sThe mass of water collected in the car is determined by applying the principle of conservation of linear momentum as shown below;
[tex]m_cu_c = v(m_c + m_w)\\\\5000 \times 22 = 20(5000 + m_w)\\\\110,000 = 100,000 + 20m_w\\\\20m_w = 10,000\\\\m_w = \frac{10,000}{20} \\\\m_w = 500 \ kg[/tex]
Thus, the mass of the water collected in the car due to the rain is 500 kg.
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what is the formula to calculate net force
Answer:
If N is the number of forces acting on a body, the net force formula is given by, FNet = F1 + F2 + F3
Explanation:
Someone help thanks
Which statement did Kepler’s investigations of the movement of the planets explain?
Jupiter has more moons than earth.
Gravity acts on all objects in the universe.
The sun is more massive than earth.
Earth is not the center of the universe.
Answer:
earth is not the center of the universe
Explanation:
i just took the test
Kepler's laws allow us to find that the correct answer, the basis is these is
d) Earth is not the center of the universe.
Kepler made extensive measurements and created a mathematical model of the movement of the planets around the sun, these analyzes are written in the form of three laws
Kepler's first law. Says the planets move elliptically Kepler's second law. Establish that the vector from the sun to the planet sweeps equal area in equal time intervals Kepler's third law. It is an application of Newton's second law to the movement of the planets around the sun, it gives a relationship between the period of the orbit and the semi-major axis of the ellipse.
[tex]T^2 = ( \frac{4\pi ^2}{G M_s} ) \ a^3[/tex]
Where T is the period, a the major axis, G the universal gravitational constant and [tex]M_s[/tex] the most of the sun.
When analyzing these Kepler's laws in all the sun is the center of movement.
Let's analyze the different claims;
a) False. The laws are not on a specific planet
b) False. Gravity is not in Kepler's laws
c) False. A ratio of the masses between planets and the sun is not established
d) True. In the laws the sun is the center of movement, therefore the earth is not the center of the universe.
In conclusion using Kepler's laws we can find that the correct answer for the bases of these is:
d) Earth is not the center of the universe.
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what sphere on earth includes mountains
The stars in the model below are arrange by.... *
Answer:
where is the picture of star
1. A wave has a wavelength of 5 m and a frequency of 2 Hz. At what speed/velocity does the
wave travel?
2. The speed/velocity of a wave on a guitar string is 100m/s and the frequency is 1,000 Hz. What
is the wavelength of the wave?
3. If the speed/velocity of a wave is 25 m/s and the wavelength is 5 m, what is the frequency of
this wave?
Answer:
1.10m/s
2.0.1m
3.5Hz
Explanation:
v=velocity, f=frequency and T=wavelength
1.v=ft
v=2x5
=10m
2.v=ft
100=1000T
divide both sides by 1000
T=0.1m
3.v=fT
25=5f
divide both sides by 5
f=5Hz
You pass 633 nm laser light through a narrow single slit of width 0.24 mm and observe the diffraction pattern on a screen 6.0 m away. If the intensity at the central bright is Io , what is the intensity at a point on the screen 3.0 mm from the center of the pattern?
Answer:
The intensity is [tex] I = 0.0175I_o [/tex]
Explanation:
From the question we are told that
The wavelength is [tex]\lambda = 633 \ nm = 633*10^{-9} \ m[/tex]
The width of the slit is [tex]d = 0.24 \ mm = 0.00024 \ m[/tex]
The distance from the screen is [tex]D = 6.0 \ m[/tex]
The distance of the position considered from the center is [tex]y = 3.0 \ mm = 0.003 \ m[/tex]
Generally the intensity from at a point on the screen 3.0 mm from the center of the pattern is
[tex]I = I_o * \frac{sin^2 [\frac{\pi d * y}{ \lambda D } ]}{[\frac{\pi d * y }{\lambda D} ]^2}[/tex]
Here [tex]I_o[/tex] is the intensity of the central bright fringe
=> [tex] I = I_o * \frac{sin^2 [\frac{3.142 * 0.00024 * 0.003}{ 633*10^{-9} * 6 } ]}{[\frac{3.142*0.00024 * 0.003 }{633*10^{-9} * 6} ]^2}[/tex]
=> [tex] I = 0.0175I_o [/tex]
what's the answers for all of the questions ?///
In order for a protostar to transition to a full fledge star, what must happen? options: A. Nuclear fusion must occur in the protostar B. Planets must form around the protostar
C. The protostar must cool down D. Accretion must occur in the rings around the protostar
We can see here that in order for a protostar to transition to a full fledge star, A. Nuclear fusion must occur in the protostar
What is protostar?A protostar is a massive cloud of gas and dust in space that has the potential to become a star and is currently collapsing due to its own gravity. It is the initial stage of a star's development.
The protostar will continue to collapse and get hotter and denser until the conditions are right for nuclear fusion, when it will fuse and turn into a star.
A star gets its energy through nuclear fusion, which is the process of joining atomic nuclei to create heavier atoms. The star is not hot enough or thick enough during the protostar phase for nuclear fusion to take place.
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If you have a fragment of glass that weighs 5 grams and has a volume of 2.4
g/ml, what is the density?
A)12 g/mL.
B)7.4 ml/g
C)2.08 g/ml
D)0.48 ml/g
Answer:
C)2.08 g/ml
Explanation:
density = [tex]\frac{mass}{vloume\\}[/tex]
=[tex]\frac{5}{2.4}[/tex]
=2.08g/ml
A ball is thrown directly downward at 4 m/s from the edge of a high cliff. If needed, use g = 10 m/s2. With zero air resistance, the distance the ball falls during its third second of fall is most nearly
28 m
4 m
29 m
12 m
57 m
Answer:
57 meters
Explanation:
Let's see what variables we have in this problem:
[tex]v_i \ \ \ \ \ \ \ t \\ v_f \ \ \ \ \ \ \triangle x \\ a[/tex]Let's set the upwards direction to be positive and the downwards direction to be negative.
We are given the initial velocity, 4 m/s. Since the ball is thrown directly downward, we can say that the initial velocity = -4 m/s.
We are also given the acceleration due to gravity, and since the acceleration is pointing downwards, we can say that a = -10 m/s².
The time is also given to us; the question wants to know the vertical displacement at time = 3 seconds, so we can plug in 3 seconds for t.
Since we are solving for vertical displacement, we can use [tex]\triangle x[/tex] as one of our variables.
Now we have all of the variables except for the final velocity, [tex]v_f[/tex].
Since we are dealing with constant acceleration, we can use this constant acceleration equation:
[tex]x_f=x_i+v_it+\frac{1}{2}at^2[/tex]Subtract [tex]x_i[/tex] from both sides to get [tex]\triangle x[/tex].
[tex]\triangle x =v_it+\frac{1}{2}at^2[/tex]Substitute in the known values:
[tex]\triangle x = (-4\frac{m}{s})(3s) + \frac{1}{2}(-10\frac{m}{s^2})(3s)^2[/tex]Get rid of the units to make the equation more readable.
[tex]\triangle x = (-4)(3) + \frac{1}{2} (-10)(3)^2[/tex]Simplify the equation and solve for delta x.
[tex]\triangle x=(-12) -5(9)[/tex] [tex]\triangle x =-12-45[/tex] [tex]\triangle x = -57[/tex]The vertical displacement is -57 meters, so we can say that the distance the ball falls in 3 seconds is most nearly 57 meters.
Suppose the spark plug on a heat engine is not functioning properly which statement best explains how this will affect the engine?
Answer:
B. Burned gas...
Explanation:
The statement explains the importance of enzymes that check for and repair mistakes during DNA replication is the enzymes prevent many genetic mutations from being expressed.
What is RNA polymerase?RNA polymerase is an enzyme that aids in the transcription of DNA into RNA during transcript in the nucleus. The enzymes prevent many genetic mutations from being expressed.
Primase is an enzyme that synthesizes short RNA sequences called primers. These primers serve as a starting point for DNA synthesis during replication as the DNA polymerases cannot begin the synthesis of the new strand, they only extend it after primase begins it and primase produces RNA molecules, the enzyme can be said to be a type of RNA polymerase.
Therefore, The statement explains the importance of enzymes that check for and repair mistakes during DNA replication is the enzymes prevent many genetic mutations from being expressed.
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A racecar accelerates uniformly from 18.5 mil to 46.1 m/s in 2.47 seconds.
What is the acceleration of the car?*
Answer:
The acceleration of the racecar is [tex]\mathbf{11.17~m/s^2}[/tex]
Explanation:
Uniformly Accelerated Motion
It's a type of motion in which the velocity of an object changes by an equal amount in every equal period of time.
Following the definition above, the acceleration is defined as:
[tex]\displaystyle a=\frac{v_f-v_o}{t}[/tex]
Where a is the constant acceleration, vo the initial speed, vf the final speed, and t the time.
The racecar goes from vo=18.5 m/s to vf=46.1 m/s in t=2.47 seconds, thus the acceleration is:
[tex]\displaystyle a=\frac{46.1-18.5}{2.47}[/tex]
[tex]\displaystyle a=\frac{27.6}{2.47}[/tex]
[tex]a = 11.17~m/s^2[/tex]
The acceleration of the racecar is [tex]\mathbf{11.17~m/s^2}[/tex]
If a pendulum makes 10 oscillations in 5 seconds, what is its oscillation frequency?
Answer:
[tex] \boxed{ \rm{Frequency = 2 hertz}}[/tex]
Explanation:
We know that,
"Frequency refers to the number of occurrences of a periodic event per time and is measured in cycles/second."
According to Question,
⇒ 5 seconds = 10 oscillations
⇒ 1 second = 10/5 oscillations
⇒ 1 second = 2 oscillations
In one second, there are 2 oscillations or cycles. The unit of frequency is Hertz. Hence, the frequency is 2 Hertz.
24. Which of the following is true for a generator?
A. It transforms thermal energy to electrical energy.
B. It transforms mechanical energy into electrical energy.
C. It transforms electrical energy into mechanical energy.
D. It transforms solar energy into electrical energy.
Answer:
The answer is b: mechanical to electrical