That is an opinion. Opinion is not fact, although it can be based upon fact.
Explanation:
given solution
h=45m v^2=u^2+2gh
g=10m/s^2 v^2=0^2+2×10m/s^2×45m
vi=0 v^2=900m^2/s^2
Answer:
They collide, couple together, and roll away in the direction that <u>the 2m/s car was rolling in.</u>
Explanation:
We should start off with stating that the conservation of momentum is used here.
Momentum = mass * speed
Since, mass of both freight cars is the same, the speed determines which has more momentum.
Thus, the momentum of the 2 m/s freight car is twice that of the 1 m/s freight car.
The final speed is calculated as below:
mass * (velocity of first freight car) + mass * (velocity of second freight car) = (mass of both freight cars) * final velocity
(m * V1) + (m * V2) = (2m * V)
Let's substitute the velocities 1m/s for the first car, and - 2m/s for the second. (since the second is opposite in direction)
We get:

solving this we get:
V = - 0.5 m/s
Thus we can see that both cars will roll away in the direction that the 2 m/s car was going in. (because of the negative sign in the answer)
D. Using a fixed-pulley system
Answer:
The temperature is 
Explanation:
From the question ewe are told that
The rate of heat transferred is 
The surface area is 
The emissivity of its surface is 
Generally, the rate of heat transfer is mathematically represented as

=> ![T = \sqrt[4]{\frac{P}{e* \sigma } }](https://tex.z-dn.net/?f=T%20%20%3D%20%20%5Csqrt%5B4%5D%7B%5Cfrac%7BP%7D%7Be%2A%20%5Csigma%20%7D%20%7D)
where
is the Boltzmann constant with value 
substituting value
![T = \sqrt[4]{\frac{13.1}{ 0.287* 5.67 *10^{-8} } }](https://tex.z-dn.net/?f=T%20%20%3D%20%20%5Csqrt%5B4%5D%7B%5Cfrac%7B13.1%7D%7B%200.287%2A%205.67%20%2A10%5E%7B-8%7D%20%7D%20%7D)
