Explanation:
It is given that,
Total mass is 70 kg
The truck exerts a constant force of 20 N.
Then the net force is given by :
F = ma
a is acceleration of rider
Initial velocity of rider is 0. So, using equation of kinematics to find the final velocity as :
Since, 1 m/s = 2.23 mph
4.28 m/s = 9.57 mph
So, the speed of the rider is 4.28 m/s or 9.57 mph.
As we know that here no air resistance while ball is moving in air
So here we will say that
initial total energy = final total energy
here we know that
(as it will be on ground at initial and final position)
so we will say
since mass is always conserved
so we will say that final speed of the ball must be equal to the initial speed of the ball
so we have