10. Which situation is an example of Newton’s third law of motion? *
1 point
A.A ball in a vacuum container moves in a straight line at a constant velocity.
B.A ball in a vacuum container accelerates when kicked with a great amount of force.
C.A person riding in a forward-moving car continues to move forward when the car stops suddenly.
D.A person in a canoe moves the paddle backward in the water, and the canoe moves forward in the water.
A. is first law, momentum constant
B. is second law, force = rate of change of momentum
C. is first law again, no force to change momentum
D. is third law, force back on water results in force forward on canoe.
D.A person in a canoe moves the paddle backward in the water, and the canoe moves forward in the water.
To determine which situation is an example of Newton's third law of motion, let's first understand what Newton's third law states.
Newton's third law of motion states that for every action, there is an equal and opposite reaction. In other words, when one object exerts a force on a second object, the second object exerts an equal and opposite force back on the first object.
Looking at the given options:
A. A ball in a vacuum container moves in a straight line at a constant velocity.
This situation describes an object in motion with no external forces acting upon it. Newton's third law is not applicable here since there is no interaction with another object.
B. A ball in a vacuum container accelerates when kicked with a great amount of force.
While this situation does involve a force being exerted on an object (the ball), it doesn't demonstrate Newton's third law. The law states that the reaction force is equal and opposite to the action force. In this case, the reaction force does not necessarily act back on the person who kicked the ball.
C. A person riding in a forward-moving car continues to move forward when the car stops suddenly.
This situation also does not exemplify Newton's third law. The person's continued forward motion is due to inertia, which is the tendency of an object to resist changes in its motion. There is no direct interaction between two objects with equal and opposite forces.
D. A person in a canoe moves the paddle backward in the water, and the canoe moves forward in the water.
Option D is the correct answer. This situation demonstrates Newton's third law. When the person pushes the paddle backward in the water, they exert a force on the water. According to Newton's third law, the water exerts an equal and opposite force on the paddle. This reaction force propels the canoe forward in the water.
So, the correct answer is D.