Consider a situation in which your car, when coasting down a straight downhill road, acquires a constant velocity.
In this situation:
a. gravity is the only force on the car
b. friction is the only force acting on the car
c. the net force acting on the car is zero
d. there must be some net force acting on the car since it is moving
Give me a break.
Netforce= ma but here a is zero (constant velocity), so net force is ..
The correct answer is c. the net force acting on the car is zero.
When the car is coasting down a straight downhill road and acquires a constant velocity, it means that the car's acceleration is zero. According to Newton's Second Law of Motion, when an object has zero acceleration, the net force acting on it must be zero.
In this situation, while gravity is indeed acting on the car, it is counteracted by another force, most likely friction. Friction opposes the motion of the car and balances out the force of gravity to maintain a constant velocity. Therefore, both gravity and friction cancel each other out, resulting in a net force of zero on the car.