Question

A cannon fires a ball vertically upward from the Earth’s surface. Which one of the following statements concerning the net force acting on the ball at the top of its trajectory is correct?a) The net force on the ball is instantaneously equal to zero newtons at the top of the flight path.b) The direction of the net force on the ball changes from upward to downward.c) The net force on the ball is less than the weight, but greater than zero newtons.d) The net force on the ball is greater than the weight of the ball.e) The net force on the ball is equal to the weight of the ball.

Answer 1

Answer:

a) The net force on the ball is instantaneously equal to zero newtons at the top of the flight path.

Explanation:

At an instantenous time at the top of the flight path, the upward force due to the Canon explosion on the ball is just equal to the weight of the ball, this will equate the net force on the ball to zero. At this point the velocity of the ball is zero before it decends down to earth under its own weight.