Forget about the car's speed. You don't need it.
The tires spin 840 rpm. That's 840 <em>Revolutions per Minute</em> .
There are 60 seconds in 1 minute. So something that happens 840 times in 1 minute happens (840 / 60) times every second.
(840 rev per minute) / (60) = <em>14 revs per second</em> .
Answer:
8.08 x 10^-5 m
Explanation:
A = 2 mm^2 = 2 x 10^-6 m^2
Total number of electrons, N = 9.4 x 10^18
time, t = 3 s
n = 5.8 x 10^28 electrons/ m^3
Current, i = Q / t = N x e / t = (9.4 x 10^18 x 1.6 x 10^-19) / 3 = 0.5 A
Let vd be the drift velocity.
i = n e A vd
0.5 = 5.8 x 10^28 x 1.6 x 10^-19 x 2 x 10^-6 x vd
vd = 2.7 x 10^-5 m/s
Distance traveled by the electrons = velocity x time
= vd x t = 2.7 x 10^-5 x 3 = 8.08 x 10^-5 m
By definition, speed is the integral of acceleration with respect to time.
We have then:
As the acceleration is constant, then integrating we have:
Where,
vo: constant of integration that corresponds to the initial velocity
We observe then that the speed varies linearly when the acceleration is constant
.
Therefore, for constant acceleration, the velocity is changing.
Answer:
an object with a constant acceleration always have:
A. changing velocity
Heat lost or gained, H = mc(θ₂ - θ₁)
Where m = mass, c = Specific heat capacity, θ₂= final temperature, θ₁ = initial temperature
m = 200g, c = 0.444 J/g°C, θ₁ = 22 °C (Since it was cooled).
H = 6.9 kj = 6.9 *1000J = 6900 J
6900 = 200*0.444* (θ₂ - 22)
6900/(200*0.444) = θ₂ - 22
77.70 = θ₂ - 22
θ₂ - 22 = 77.7
θ₂ = 77.7 + 22 = 99.7
So initial temperature before cooling ≈ 100°C . Option C.
A ball falling through the air has a mass, a density, a volume...it is facing air resistance and is being acted on by gravity...it is accelerating and gaining velocity...and it is increasing in kinetic energy.
I suppose out of all those the biggest thing the ball has in this case is ENERGY. There are two main types to focus on...
Kinetic Energy - The further the ball fall the more KE it has...until terminal velocity is reach, then KE would become constant.
Potential Energy - Conversely to that of KE, the further the ball falls the less PE it will have.
<em>Heat/Thermal Energy is technically also present due to the friction from the air resistance, but the transfer of energy between the air and ball is quite complex and not necessary important for basic physics.
</em>
The question itself seem kind of vague and open ended, but I could just be viewing it the wrong way.
Comment if you need more help!
