Problem: Kinematics #1

A stone is released from a height of 20 m and allowed to fall in a straight line towards the ground. Ignoring air resistance, calculatea) the time taken for the stone to reach the ground.b) the velocity of the stone just before it touches the ground(Assume that g = 10 m s-2)SolutionShow solution >>The answers for (a) and (b) are 2 seconds and 20 m s-1 respectively.This is a problem utilising the

Problem: Waves #1

The frequency of oscillation of a simple pendulum is f1. When the length of the pendulum l is increased to 2l, the frequency of oscillation of the simple pendulum is f2. The value of the ratio f1/f2 isSolutionShow solution >> The answer is D.The formula for the periodic time, T of a simple pendulum is given byand we know thatTherefore, the formula for f of a simple pendulum is given byNow we know