a 1200kg car is moving at a steady speed of 25 m/s down a level road. The engine is exerting a steady force of 800N. What is the force of resistance the motor is overcoming?
Steady speed? That means no net accelerating force, so, friction must be 800N.
To find the force of resistance the motor is overcoming, we need to take into account the net force acting on the car.
First, let's calculate the force of resistance. The force of resistance is equal to the net force acting on the car, which is given by Newton's second law of motion:
Net Force = Mass x Acceleration
Since the car is moving at a steady speed, the acceleration is zero. Therefore, the net force is also zero.
Now, let's calculate the net force:
Net Force = Force of Engine - Force of Resistance
Since the net force is zero, we can write the equation as:
0 = 800N - Force of Resistance
To find the force of resistance, we rearrange the equation:
Force of Resistance = 800N
So, the force of resistance the motor is overcoming is 800 Newtons.