How much work must be done by a force on 50 kg body in order to accelerate it from rest to 20m/s in 10s?

Options

A. `10^3 J `
B. `10^4 J `
C. `2 xx 10^3 J `
D. `4 xx 10^4 J `

Answer

B

Explanation

Now, `s = u t + 1/2 a t^2`
`s = 0 + 1/2 xx 2 xx 10 xx 10 `
`s= 100m `
Hence, work done
`W = F xx S`
`W = ma xx S`
`W = 50 xx 2 xx 100`
`W = 10000 = 10^4 J`