Question

A train starting from rest accelerates uniformly for 100 s, then comes to a stop with a uniform retardation in the next 200 s. During the motion, it covers a distance of 3 km. Choose the wrong option
A. Its acceleration is `0.2 m//s^(2)`
B. Its retardation is `0.1 m//s^(2)`
C. The maximum velocity is `20 m//s`
D. The maximum velocity is `10 m//s`

Answer 1

Correct Answer - D

Area of v-t graph=displacement
`1/2vxx300=3000impliesv=20 m//s`
Maximum velocity`=20 m//s`
Acceleration `a_(1)=v/100=20/100=0.2 m//s^(2)`
Retardation `a_(2)=v/200=20/200=0.1 m//s^(2)`