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).

Answer

B, C

Explanation

`m=1400kg`
`v=54km/h=15m/sec`
`h=10m`
Work done= (total K.E.)-total P.E.`
=(1/20mv^2-mgh`
`=1/2xx1400xx(15)^2-1400xx9.8xx10`
`=[phone]=20300j`
`so, work done against friction `W_1=20300J`