suppose you exert 150N on your refrigerator and push it across the kitchen floor at constant velocity.
a. is the friction force equal and opposite to your 200N push? explain
b. does the friction force make up the reaction force to your push?
This question is flawed.
what does that mean?
To understand the situation, let's break it down:
a. Is the friction force equal and opposite to your 200N push?
When you push the refrigerator with a force of 150N, the refrigerator moves at a constant velocity. This means that the net force acting on the refrigerator is zero, as there is no acceleration. Therefore, there must be another force present that is equal in magnitude and opposite in direction to your push (150N).
In this case, the friction force comes into play. The friction force acts in the opposite direction to the motion, providing the necessary opposing force to balance the pushing force. Since the refrigerator is moving at a constant velocity, the friction force must be equal in magnitude to your push of 150N.
Hence, the friction force is equal and opposite to your 150N push, not 200N.
b. Does the friction force make up the reaction force to your push?
The reaction force to your push of 150N is not the friction force itself. It's important to note that according to Newton's third law of motion, for every action, there is an equal and opposite reaction.
In this scenario, the reaction force to your push is the normal force exerted on the refrigerator by the floor. The normal force acts perpendicular to the surface between the refrigerator and the floor. It counteracts the force of gravity on the refrigerator and provides the necessary support. The friction force, on the other hand, is parallel to the floor and opposes the motion.
So, the reaction force to your push is the normal force, not the friction force.