A 710kg car drives at a constant speed of 23m/s .
A 710kg car drives at a constant speed of 23m/s . It is subject to a drag force of 500 N. What power is required from the car's engine to drive the car (a) on level ground?
1 answer
The correct answer for聽A 710kg car drives at a constant speed of 23m/s .聽It is subject to a drag force of 500 N. What power is required from the car's engine to drive the car (a) on level ground?
(a) 11500 W
The power required for the car's engine is given by
P = Fv
where
F is the force that the engine must apply
v = 23 m/s is the velocity of the car
In this situation,the car is moving at constant velocity: this means that its acceleration is zero, so the net force on the car must be zero. Since there is a drag force of 500 N against the motion of the car, this means that the force applied by the engine in the forward direction must also be 500 N:
F = 500 N
So the power erogated by the engine is
P = (500 N)(23 m/s)= 11500 W
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