Answer:
The new speed of the ball is 176.43 m/s
Explanation:
Given;
mass of the ball, m = 7 kg
initial speed of the ball, u = 5 m/s
applied force, F = 300 N
time of force action on the ball, t = 4 s
Apply Newton's second law of motion;
where;
v is new speed of the ball
Therefore, the new speed of the ball is 176.43 m/s
Answer:
Straight line graph attached showing mechanical energy on x-axis and altitude y on y-axis
Explanation:
As mechanical energy is the sum of kinetic energy and potential energy, the ball at a height H possesses potential energy= m.g.H
and Kinetic energy= 0.
But the sum of both energies is equal to m.g.H.
When the ball starts moving, the height starts to decrease and potential energy also decreases with decreasing y. On the other hand kinetic energy starts increasing with decreasing Y. But their sum remains constant i.e equal to mechanical energy. It remains same until the ball touches the ground. The graph attached shows height H or altitude y on x-axis and Mechanical Energy on y-axis. It shows a straight horizental line showing that mechanical energy remains same as y decreases.
