Question

A boy uses a slingshot to launch a pebble straight up into the air. The pebble reaches a height of 38.0 m above the launch point 1.0 seconds later. Assume air resistance is negligible.

(a) What was the pebble's initial speed (just after leaving the slingshot)?
42.9 m/s

(b) How much time did it take for the pebble to first reach a height of 19.0 m above its launch point?
? s

You toss a tennis ball straight upward. At the moment it leaves your hand it is at a height of 1.3 m above the ground, and it is moving at a speed of 6.0 m/s.

(a) How much time does it take for the tennis ball to reach its maximum height?
?s

(b) What is the maximum height above the ground that the tennis ball reaches?
  3.13 m

(c) When the tennis ball is at a height of 2.6 m above the ground, what is its speed?
?m/s

Answer 1

a) Initial Speed,

b)  

Solving for t ;

Initial Speed,

a) Time for Maximum height

b) Maximum height,

c)