Question

A ball thrown vertically upward is caught by the thrower after 2.00 s. Find (a) the initial speed of the ball and (b) the maximum height the ball reaches.

Answer 1

(a) The ball has some initial speed v₀ (which we don’t know). We know the acceleration of the ball, namely a = −g = −9.80 m/s² . We also know that

at t = 2.00 s the y coordinate of the ball was zero. (As usual, we say the ball starts off at y = 0.) 

(b) We know that at maximum height the velocity v is zero. We can use.

so the maximum height attained by the ball was 4.90 m.