answer :
Visible: Our eyes detect visible light. Fireflies, light bulbs, and stars all emit visible light. Ultraviolet: Ultraviolet radiation is emitted by the Sun and are the reason skin tans and burns. "Hot" objects in space emit UV radiation as well.
Which objects emit electromagnetic waves?
All objects emit electromagnetic radiation according to their temperature. Colder objects emit waves with very low frequency (such as radio or microwaves), while hot objects emit visible light or even ultraviolet and higher frequencies.
9. An efficient LED light bulb uses energy at a rate of 7 watts or 7 J/second. What
total amount of electrical energy is used if the light is on for 2 hours?
Answer: 50,400 J
Explanation:
A driver sees a boy and his dog in the road, and it takes the driver 0.50 seconds to put on the brakes. If the car travels 14 meters during that time, what is its velocity?
Answer:
The answer would be 91.9 or 91.8635
Hope this helps
A driver sees a boy and his dog on the road, and it takes the driver 0.50 seconds to put on the brakes, If the car travels 14 meters during that time, the velocity of the car would have been 56 m/s,
What are the three equations of motion?There are three equations of motion given by Newton
The first equation is given as follows
v = u + at
the second equation is given as follows
S = ut + 1/2×a×t²
the third equation is given as follows
v² - u² = 2×a×s
As given in the problem a driver sees a boy and his dog on the road, and it takes the driver 0.50 seconds to put on the brakes, If the car travels 14 meters during that time,
t = 0.5 s , s = 14 m
By using the first equation of the motion,
v = u+at
0 = u+a×0.5
a = -2u m/s²
Now by using the second equation of motion,
s = ut+1/2at²
By substituting t=0.5 and a = -2u m/s² in the equation ,
14 = u/2-u/4 = u/4
u = 56 m/s
Thus, the velocity of the car would have been 56 m/s,
Learn more about equations of motion from here,
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I WILL GIVE BRAINLIEST!!!! Your friend stands on the roof of her house, which is 12.2 m off the ground, and kicks a soccer ball to you so that it is initially moving horizontally at 13.9 m/s. What is its speed as it hits the ground? The time is 1.58 seconds.
Answer:
16.74 m/s
Explanation:
From the question, the parameters given are:
Height h = 12.2 metres
Initial velocity U = 13.9 m/s
Time t = 1.58 s
The range or distance covered by the ball will be
R = u^2/g
Where g = 9.8 m/s^2
R = 13.9^2/9.8
R = 193.21/9.8
R = 19.72 m
Let first calculate the acceleration by using the formula below
R = Ut + 1/2at^2
Substitute all the parameters into the formula
19.72 = 13.9 × 1.58 - 1/2 × a × 1.58^2
19.72 = 21.962 - 1.2482a
Collect the like terms
-1.2482a = 19.72 - 21.962
- 1.2482a = - 2.242
a = 2.242/1.2482
a = 1.796 m/s^2
Using equation 1 to find the final speed
V = U + at
V = 13.9 + 1.796 × 1.58
V = 13.9 + 2.838
V = 16.74 m/s
Therefore, it hit the ground at speed 16.74 m/s
Calculate the peak voltage of a generator that rotates its 200-turn, 0.100 m diameter coil at 3600 rpm in a 0.800 T field.
Answer:
The peak voltage is 473.86 V
Explanation:
Given;
number of turns of generator, N = 200 turn
diameter of the coil, d = 0.1 m
radius of the coil, r = 0.05 m
Magnitude of the magnetic field, B = 0.8 T
angular frequency, ω = 3600 rpm
angular frequency, ω (rad/s) = [tex]\frac{2\pi}{60} *3600\ rpm = 377.04 \ rad/s[/tex]
The peak voltage is given by;
E = NBAω
Where;
A is the area of the coil = πr² = π (0.05)² = 7.855 x 10⁻³ m²
E = (200)(0.8)(7.855 x 10⁻³)(377.04)
E = 473.86 V
Therefore, the peak voltage is 473.86 V
34. A chain of hamburger restaurants advertises that it
has sold more than 50 billion hamburgers over the
years. Estimate how many pounds of hamburger
meat must have been used by the restaurant chain
to make 50 billion hamburgers and how many head
of cattle were required to furnish the meat for these
hamburgers.
Answer:
"12.50 × 10⁹" pounds of hamburger. The further explanation is given below.
Explanation:
Sold hamburger
= more than 50 billion
To get pounds of hamburger,
= [tex]50 \ billion\times 0.125 \ lbs[/tex]
= [tex]12.50 \ billion \ pounds[/tex]
= [tex]12.50\times 10^9 \ lb[/tex]
On divide pounds of hamburgers by pounds of burger meat through one head of cattle, we get
⇒ [tex]\frac{12.5 \ billion}{350}[/tex]
⇒ [tex]35714285 \ cattle[/tex]
What are the 2 main parts of physical science
Answer:
Physical science is the study of the inorganic world. That is, it does not study living things. (Those are studied in biological, or life, science.) The four main branches of physical science are astronomy, physics, chemistry, and the Earth sciences, which include meteorology and geology.
Explanation:
How does work affect energy between objects so it can cause a change in the form of energy? Work transfers energy. Work changes energy. Work increases energy. Work decreases energy.
Answer:
Work can transfer energy between objects and cause a change in the amount of total energy. Work can transfer energy between objects and cause a change in the form of energy. ... When a spring is compressed, the energy changes from kinetic to potential.
Answer:
I think its either A or B
Explanation:
Duas cargas elétricas Q¹= 15.10-seis ao quadrado C e Q² = 150.10-seis ao quadrado, estão separadas por uma distância de 0,1m, no vácuo. Determine a intensidade da força elétrica de repulsão existente entre as cargas. Dá uma força ae clã!
Answer:
The electric field intensity of electric force is [tex]1.35\times10^{7}\ N/C[/tex]
Explanation:
Given that,
First charge [tex]q_{1}=15\times10^{-6}\ C[/tex]
Second charge [tex]q_{2}=150\times10^{-6}\ C[/tex]
Distance = 0.1 m
We need to calculate the electric field intensity of electric force
Using formula of intensity of electric force
[tex]E=\dfrac{F}{q_{2}}[/tex]
[tex]E=\dfrac{kq_{1}}{r^2}[/tex]
Put the value into the formula
[tex]E=\dfrac{9\times10^{9}\times15\times10^{-6}}{(0.1)^2}[/tex]
[tex]E=13500000\ N/C[/tex]
[tex]E=1.35\times10^{7}\ N/C[/tex]
Hence, The electric field intensity of electric force is [tex]1.35\times10^{7}\ N/C[/tex]
Which of the following is a chemical property of matter?
combustibility
weight
electrical conductivity
odor
Answer:
The correct answer is combustibility
Explanation:
A chemical property of a matter is a property in which a matter has the tendency to change its form through chemical reaction(s).
A matter is said to have combustibility property if it can undergo combustion. Combustion is a chemical process in which a substance burns in excess oxygen to produce carbon dioxide and water.
Consider the equation below
CH₄ + O₂ ⇒ CO₂ + H₂O
The equation above shows methane burning in excess oxygen to produce carbon dioxide and water
The answer is electrical conductivity!
1.) Identify two types of heat?
One type of heat causes a change in temperature, the other type of heat causes a change of state.
Answer:
Explanation:
Thermal Energy and Heat
Shards of ice fly from the sculptor’s chisel. As the crowd
looks on, a swan slowly emerges from a massive block of ice. As
the day wears on, however, drops of water begin to fall from the
sculpture. Drip by drip, the sculpture is transformed into a puddle of liquid water. What makes matter change from one state to
another? To answer this question, you need to think about the
particles that make up matter.
Energy Simply stated, energy is the ability to do work or cause
change. The energy of motion is called kinetic energy. Particles
within matter are in constant motion. The amount of motion of
these particles depends on the kinetic energy they possess. Particles
with more kinetic energy move faster and farther apart. Particles
with less energy move more slowly and stay closer together.
The total kinetic energy of all the particles in a sample of
matter is called thermal energy. Thermal energy, an extensive
property, depends on the number of particles in a substance as
well as the amount of energy each particle has. If either the
number of particles or the amount of energy in each particle
changes, the thermal energy of the sample changes. With identically sized samples, the warmer substance has the greater thermal energy.
A hollow steel shaft is to transmit 4200 n.m of torque and is to be sized so that the torsional stress does not exceed 120 mpa
A hollow steel shaft is to transmit 4200 n.m of torque and is to be sized so that the torsional stress does not exceed 120 Mpa
If the inside diameter is 70 percent of the outside diameter, what size shaft should be used?
Answer:
the preferred outer diameter of the hollow steel shaft obtained a little bit higher than 61.67 mm is 80 mm
the preferred inner diameter of the hollow steel obtained a little bit lower than 56 mm is 50 mm
Explanation:
From above;
let the inside diameter be [tex]d_i[/tex]
let the outside diameter be [tex]d_o[/tex]
Then
[tex]d_i[/tex] = 70% [tex]d_o[/tex]
[tex]\dfrac{d_i}{d_o} = \dfrac{70}{100}[/tex]
[tex]\dfrac{d_i}{d_o} =0.7[/tex] ------ (1)
to determine the outer diameter of the hollow steel shaft by using the equation of the torque, we have:
[tex]T = \dfrac{\pi}{16} \times \tau \times d_o^3 ( 1 - (\dfrac{d_i}{d_o})^4)[/tex]
where;
[tex]\tau[/tex] = torsoinal shear stress = 120 MPa
[tex]4200= \dfrac{\pi}{16} \times 120\times 10^6 \times d_o^3 ( 1 - 0.7)^4)[/tex]
[tex]4200= 0.19635 \times 120\times 10^6 \times d_o^3 (0.7599)[/tex]
[tex]4200=17904763.8 \ d_o^3[/tex]
[tex]d_o^3 = \dfrac{4200}{17904763.8}[/tex]
[tex]d_o^3 = 2.3457 \times 10^{-4}[/tex]
[tex]d_o =\sqrt[3]{2.3457 \times 10^{-4}}[/tex]
[tex]d_o =0.06167 \ m[/tex]
[tex]d_o =0.06167 \ m \times (\dfrac{1000 \ mm}{1 \ m})[/tex]
[tex]d_o =61.67 \ mm[/tex]
From the tables of A-17 of sized and Renard Numbers,
the preferred outer diameter of the hollow steel shaft obtained a little bit higher than 61.67 mm is 80 mm
However, from equation (1)
[tex]\dfrac{d_i}{d_o} =0.7[/tex] ------ (1)
replacing the value of [tex]d_o[/tex]
[tex]\dfrac{d_i}{80} =0.7[/tex]
[tex]d_i = 80 \times 0.7[/tex]
[tex]d_i = 56 \ mm[/tex]
From the tables of A-17 of sized and Renard Numbers,
the preferred inner diameter of the hollow steel obtained a little bit lower than 56 mm is 50 mm
K= 1/2mv^2
K=1/2(210kg)(10.5 m/s)^2
answer:
unit:
Answer:
11577.25 JoulesExplanation:
The expression given in the question which is
[tex]k= \frac{1}{2} mv^2[/tex]
Is the expression for the kinetic energy stored in a system and it is measured in Joules
From the expression we can see that
mass m=210 kg
velocity v= 10.5 m/s
Substituting as seen in the question we have the kinetic energy as
[tex]k= \frac{1}{2}*210*10.5^2\\\\k= \frac{1}{2}*210*110.25\\\\k= \frac{1}{2} *23152.5\\\\k= 11577.25 J[/tex]
hence the energy stored is 11577.25 Joules
Explain newton 2nd law ???
Explanation:
Newton's second law simply says that the net force on an object is equal to the object's mass times its acceleration.
∑F = ma
For example, think of a game of tug-of-war, in which two teams pull on a rope in opposite directions.
If the forces are equal (balanced), then the net force is 0 N, so Newton's second law tells us that the rope's acceleration is 0 m/s².
If the forces are not equal (unbalanced), then the net force is not 0 N, and the rope will accelerate in the direction of the net force.