Answer:
<h2>the car must move with the speed</h2><h2>

</h2>
Explanation:
As we know that the momentum of the car and truck is same
so as per the formula of momentum we have

so we have

so we will have


So the car must move with the speed

A=mgh
m=300g=0.3kg
g=9,81 m/s^2
h=10m
A=29.43J
Answer:
C) 40,000 Joules
Explanation:
½(1000)10² - 10000 = 40000