A roller-coaster car of mass crests a hill high with a speed of

PHYSICS · Single correct · CBSE · Physics · Work, Energy and Power · Work, Energy and Power

Problem

A roller-coaster car of mass

1200\,\text{kg}

crests a hill

25\,\text{m}

high with a speed of

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

. It then descends without friction to a valley that is

5.0\,\text{m}

above the ground. Calculate its speed in the valley. (a)

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

(b)

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

(c)

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

(d)

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