A car weighing 1400 kg is moving at speed of 54 km/h up a hill when the motor stops. If it is just able to read the destination which is at a height of 10 m above the point calculte the work done against friction (negative of the work done by the friction).

Options

A. `17500 J`
B. `12500 J`
C. `25000 J`
D. `50000 J`

Answer

A

Explanation

`v=54(km)/(h)=54xx(5)/(18)=15(m)/(s)`
`(1)/(2)mv^2=mgh+W_f`
`(1)/(2)xx1400(15)^2=1400xx10xx10+W_f`
`W_f=17500J`