Question

In an auditorium, a physics teacher uses a pendulum made by hanging a bowling ball from a wire to the ceiling. At the low point in its swing, a ball with a mass of 7.2-kg has a speed of 6 m/s. Ignoring air resistance, how high will the bob swing above the low point before reversing direction?

Answer 1

h = 1.8348 meters

Step-by-step explanation:

In this question we just need to set kinetic energy equal to gravitational potential energy. This is because all of the speed of the object will be converted to height when the object stops at the highest point.

Kinetic energy = (1/2) * m * v^2

G.P.E = m*g*h

Setting these two equal, mass cancels out.

g = 9.81 m/s^2

v = 6 m/s

so we have:

m*g*h = 0.5 * m * v^2

h = 0.5 * 6^2 / 9.81

h = 1.8348 m