A truck with a mass of 1.5 x 103 kg accelerates to a speed of 18.0 m/s in 12.0 s from a dead stop. Assume that the force of resistance is a constant 400.0 N during the acceleration. What is the average power developed by the truck’s engine?

Question

loser66 · Answer

@dan815

dan815 · Answer

you need to find the total acceleration, if it took 12 seconds to get to 18.0 m/s velocity

dan815 · Answer

err speed*

dan815 · Answer

dist=1/2at^2
velocity=a*t
18/12=a
    3/2= a
a=3/2 m/s^2

dan815 · Answer

for the truck to have a total acceleration of 3/2 m/s^2 we have to find the engines acceleration that is overcoming the deacceleration due to friction

dan815 · Answer

acceleration due to friction =
F= MA
400 = 1500 * A
a=400/1500 <--- acceleration due to friction
Therefore the total acceleration the engine must generate is
3/2 + 4/15 = (45+8)/30 =53/30 m/s^2

dan815 · Answer

uhh so Power= Force *  velocity

dan815 · Answer

power=work/time

dan815 · Answer

power=rate of work done

dan815 · Answer

work = Force * distance
so power= work / time
     power = Force * distance/time, but distance/time = speed
               = Force * speed

dan815 · Answer

speed=3/2*t
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