Physics

Problem

A rocket sled of mass

500\,\text{kg}

starts from rest on a horizontal track. Its booster provides a constant thrust of

4000\,\text{N}

forward for

8.0\,\text{s}

, while a constant frictional force of

200\,\text{N}

opposes the motion. What is the speed of the sled at the end of the

8.0\,\text{s}

interval? a)

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

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

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

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