Editor Staff asked 1 year ago
A 200 kg wagon climbs up a hill of slope 30-degrees in 1 minute at a speed of 36 km/h. How much power is delivered by the engine if the frictional force is 25% of the weight of the car? (Assume g = 10m/s^2)
(a) 25 kW
(b) 50 kW
(c) 100 kW
(d) 125 kW
I got this question in an international level competition.
Asked question is from Power in portion Work, Energy and Power of Physics – Class 11
Select the correct answer from above options
Interview Questions and Answers, Database Interview Questions and Answers for Freshers and Experience
Editor Staff answered 1 year ago
The correct answer is (a) 25 kW
Easiest explanation: Weight of car = m x g
= 200 x 10
= 2,000 N
Frictional force = (25/100) x (2,000)
= 500 N
Total force (F) = 2000 + 500
= 2,500 N
Velocity (v) = 36 km/h
= 36 x (1000/3600)
= 10 m/s
P = F x v
= 2500 x 10
= 25 kW.
