How is Work Done Calculated for a Car Accelerating Uphill?

[MMCS]

if a car of mass 980kg accelerates up an incline (10°to the horizontal) and increases its speed from 8.3m/s to 13.8m/s in 60m, both the air resistance and rolling resistance are taken as constant at 50N and 200N respectivelyfor the acceleration period described, determine work done

work done = Δkinetic energy + Potential energy

kinetic energy = 1/2 * mass * (v2²-v1²)
PE = mgh

work done = 1/2 * 980 * (13.8²-8.3²) + 980 * 9.81 * 60sin(10) + 50N + 200N = 161KJ

but I have the answer to be 175KJ

 

[tiny-tim]

Hi MMCS!

… + 50N + 200N = 161KJ

Anything strike you as odd about those units?

 

[MMCS]

Ah of course, multiply these forces by the the distance to get units of Nm. Thanks tiny-tim!