Question

a tractor pulls a wagon from rest with a constant force of 700 N eventually giving the wagon a speed of 20 km/h. how much work is done by the tractor in 3.5 min? whats the tractors power output?

Answer 1

Work = Force × distance

We need to calculate distance travelled.

20km/hr = 20,000m / 60min  → 333.3m/ min

333.3 × 3.5 min = 1,166.6 meters travelled

Force = 700 N  and distance = 1,166.6 m

Work done is  700 N × 1,666.6 =  816,620 Nm

Power output = work /time

Power output is 816, 620 Nm / (3.5 × 60sec) →816, 620 / 210 = 3,888.7

Power output is 3,888.7 Watts.

Power output can also be expressed in joules per second so it is also correct to  say work done is 3,888.7 J/s