The mass of the second car is 1434.21 kg
<u>Explanation:</u>
Using law of conservation of momentum,

Given:
= 1090 kg
= 11 m/s
= 0
v = 4.75 m/s
We need to find 
When substituting the given values in the above equation, we get





The acceleration of gravity on or near the Earth's surface is 9.8 m/s² downward.
Is that right ? I don't hear any objection, so I'll assume that it is.
That means that during every second that gravity is the only force on an object,
the object either gains 9.8m/s of downward speed, or it loses 9.8m/s of upward
speed. (The same thing.)
If the rock starts out going up at 14.2 m/s, and loses 9.8 m/s of upward speed
every second, it runs out of upward gas in (14.2/9.8) = <em>1.449 seconds</em> (rounded)
At that point, since it has no more upward speed, it can't go any higher. Right ?
(crickets . . .)
The answer is A). Moving from A to C the temperature and the kinetic energy increases.