A car is driven at a constant speed of 77 km/h down a road. The car's engine delivers 49 kW of power. Calculate the average force that is resisting the motion of the car.
Assistance needed.
To calculate the average force resisting the motion of the car, we need to use the equation:
Average Force = Power / Velocity
Given:
Power (P) = 49 kW
Velocity (v) = 77 km/h
First, we need to convert the velocity from km/h to m/s, as the power is given in kilowatts. To do this, we use the conversion factor: 1 km/h = 1000/3600 m/s.
Velocity (v) = 77 km/h * (1000/3600) m/s = 21.3889 m/s (rounded to 4 decimal places)
Now, we can substitute the values into the equation:
Average Force = 49 kW / 21.3889 m/s
Calculating this, we get:
Average Force = 2.2914 kN (rounded to 4 decimal places)
Therefore, the average force resisting the motion of the car is approximately 2.2914 kilonewtons.