A boy tries to hit a bird by throwing a stone vertically upward but the stone misses the bird. The stone goes upwards in the air for 3 s. While returning after 1 second the stone hits the bird. Answer the following questions based on the information given: (𝒊) Find the maximum height reached by the stone. (𝒊𝒊) At what height was the bird hit? (𝒊𝒊𝒊) What value is not shown by the boy?

(𝐢) Time of ascent = 3s Initial velocity = u Final velocity, v = 0 m/s Acceleration, a = g = - 9.8 m/s2 ∴           …

Velocity-time graph for the ball’s motion is shown in figure.

Observe the graph and answer the following questions. Assume that g = 10 m/s2 and that there is no air resistance. (a) In which direction is the ball moving at point C? (b) At which point is the ball stationary? (c) At which point is the ball at its maximum height? (d) what is the ball’s acceleration at point C? (e) What is the ball’s acceleration at point A? (f) What is the ball’s acceleration at point B? (g) At which point does the ball have the same speed as when it was thrown?

(a) Downward (b) At point B (c) At point B (d) Acceleration =10 ms-2 (e) Acceleration = -10 ms-2 (f) Acceleration =10 ms-2 (g) At point C