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 truckÍs engine?

Power = Net Force x velocity

Net force = driving force - force of resistance

Driving force = mass x acceleration

Acceleration = (final velocity - initial velocity) / time

Acceleration = (18 - 0) / 12 = 1.5 m/s²

Driving force = 1.5 x 10³ x 1.5

= 2250 N

Net force = 2250 - 400

= 1850

Power = 1850 x 18

= 3.33 x 10⁴ Watts

There are several information's already given in the question. Based on those information's the answer can be easily deduced.

Mass of the truck = 1.5 x 10^3 kg

Constant force of resistance = 400 N

Final Velocity = 18 m/s

Initial velocity = 0 m/s

Time taken = 12 s

Then

Acceleration = (Final velocity - initial velocity) / Time

= 18 / 12

= 3/2

= 1.5 m/s^2

Then

Driving force = Mass * Acceleration

= 1.5 * 10^3 * 1.5

= 2250 N

So

Net Force = 2250 - 400

= 1850 N

Average power developed = 1850 * 18

= 3.33 * 10^4 W