A 2-ton vehicle travels at 20m/s on a road where the frictional force is 10% of the weight of the vehicle. What is the power required? (Assume g = 10m/s2)
Answer & explanation
Correct answer: option 2
Weight of car = m x g
= 2000 x 10 = 20000 N
Frictional force = \(\frac{10}{100}\) x (20000)
= 2000 N
Total force (F) = 20000 + 2000 = 22000 N
Velocity (v) = 20 m/s
P = F x v
= 22000 x 20
= 440000 W = 440 kW.