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Mechanics- work energy principle and power

A car of mass 1600 kg is being driven up a hill inclined at 10 degree to the horizontal. The car has initial speed of 10 m/ s and final speed of 12 m/ s after 60 s. Air resistance and friction may be ignored. Find the average power generated by the engine.
Iam getting the ans 31180W, but textbook ans is 3600W
I first calculated acceleration using v= u+at and got a= 0.033m/s^2
Then calculated F- 16000sin10=1600×0.033 and got the ans F=2831.7N
Then calculated s using v^2= u^2+2as and got s= 660.67m
Avg power= work done/ time
Iam not getting the right ans. Pls help
Original post by Shas72
A car of mass 1600 kg is being driven up a hill inclined at 10 degree to the horizontal. The car has initial speed of 10 m/ s and final speed of 12 m/ s after 60 s. Air resistance and friction may be ignored. Find the average power generated by the engine.
Iam getting the ans 31180W, but textbook ans is 3600W
I first calculated acceleration using v= u+at and got a= 0.033m/s^2
Then calculated F- 16000sin10=1600×0.033 and got the ans F=2831.7N
Then calculated s using v^2= u^2+2as and got s= 660.67m
Avg power= work done/ time
Iam not getting the right ans. Pls help


I get a similar result to yours. (Slightly different as I was using a = 1/30). I think the book answer may have been calculated using 1600sin(10) rather than 1600gsin(10) as the force down the slope. You can confidence-check your result by working out change in KE and change in PE.
Reply 2
Original post by old_engineer
I get a similar result to yours. (Slightly different as I was using a = 1/30). I think the book answer may have been calculated using 1600sin(10) rather than 1600gsin(10) as the force down the slope. You can confidence-check your result by working out change in KE and change in PE.

Thanks a lottt!

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