The mass of a cyclist together with the bicycle is 90 kg. Calculate the work done by cyclist if the speed increases from 6km/h to 12 km/h.

Answer

C

Explanation

`M=m_c+m_b=90m`
`u=6km/h=1.666m/sec`
`v=12 km/h=3.333 m/sec`

increse in K.E. =1/2Mv^2-1/2mu^2`
`=1/2 90xx(3.333)^2-1/2xx90x(1.66)^2`
=499.4-124.6`
`=374.8=375J`