Answer:
To achieve the velocity of 40 m/sec height will become 4 times
Explanation:
We have given initially truck is at rest and attains a speed of 20 m/sec
Let the mass of the truck is m
At the top of the hill potential energy is mgh and kinetic energy is
So total energy at the top of the hill
At the bottom of the hill kinetic energy is equal to and potential energy will be 0
So total energy at the bottom of the hill is equal to
Form energy conservation
, for v = 20 m/sec
Squaring both side
h = 20.408 m
Now if velocity is 0 m/sec
h = 81.63 m
So we can see that to achieve the velocity of 40 m/sec height will become 4 times
