A ball is released from rest and after falling for some time hits the ground with a…

PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Kinematics · Kinematics

Problem

A ball is released from rest and after falling for some time hits the ground with a speed of

20\,\text{m\,s}^{-1}

. Air resistance is negligible. (a) Calculate the height through which the ball has fallen. Take

g=9.8\,\text{m\,s}^{-2}

. (b) Find the time of fall. (c) If the same ball were dropped on a planet where the acceleration due to gravity is

4.9\,\text{m\,s}^{-2}

, how long would it take to acquire the same speed of

20\,\text{m\,s}^{-1}

? Keep the initial conditions identical.