A cart rolls down a frictionless track

PHYSICS · Subjective · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

3.0\,\text{kg}

cart rolls down a frictionless track. At point A, an energy bar chart shows

0

-unit kinetic energy and

40

-unit gravitational potential energy. At point B farther down the track, the chart shows a

10

-unit potential-energy bar and a

30

-unit kinetic-energy bar. Each unit corresponds to

1\,\text{J}

. Calculate the speed of the cart at point B. Give your answer to two significant figures.