A car is driven at a constant speed of 85 km/h down a road. The car's engine delivers 49.2 kW of power. Calculate the average force that is resisting the motion of the car.
P = F•v
F= P/v =49200•3600/85000 =2084 N
To calculate the average force resisting the motion of the car, we can use the equation:
Force = Power / Velocity
Given data:
Power (P) = 49.2 kW
Velocity (V) = 85 km/h
First, let's convert the velocity from km/h to m/s.
85 km/h = 85,000 m / (60*60) s ≈ 23.61 m/s
Therefore, the velocity of the car is approximately 23.61 m/s.
Now, we can substitute the values into the equation:
Force = 49.2 kW / 23.61 m/s
To calculate the force, we need to convert kilowatts (kW) to watts (W).
1 kW = 1000 W
So, 49.2 kW = 49,200 W
Now our equation becomes:
Force = 49,200 W / 23.61 m/s
Simplifying further:
Force ≈ 2086.76 N
Therefore, the average force resisting the motion of the car is approximately 2086.76 Newtons.