Pre-interview

(beginning of the semester)

Post-interview

(end of the semester)

Interviewer prompt

Please share with me your understanding of the relationship between force and motion.

Please share with me your understanding of the relationship between force and motion after taking the course

Ahmed

Force causes motion … I need to exert a force on a car to be able to push it when it is stuck.

Before I didn’t know about uniform motion and accelerated motion. Now I can make a good connection between uniform motion and Newton’s first law. I can also see the connection between Newton’s second law and an accelerated motion. Before, I didn’t consider various forces acting on the object but now I first try to draw a free body diagram and consider all the forces acting on the object. When we learned about Newton’s laws I learned the accelerated motion and uniform motion better. For example, it made more sense to have a zero net force in uniform motion.

Bill

The applied force makes an object move.

We need a force to change the motion. When there is a force then there is an acceleration and so we deal with an accelerated motion. But there is no force on an object moving with zero acceleration.

Catherine

Force creates motion.

Well I know a lot more now. There is no friction and you push someone and he keeps moving and then you need another force to stop him or when there is a continuous force on an object then there is an acceleration.

Dan

Force, or applied force, you know, an agent that can push or pull an object. Motion is when an object is moving. There must be an agent to create motion.

We need force to create motion. The relationships between these two concepts are well explained in Newton’s laws. For example, an object in motion stays in motion unless there is a kind of force put on it.

Elena

Force makes objects move. When the applied force is gone the object stops finally. If I push a car it starts moving but it stops finally. But if the driver starts the car then it keeps going since the engine provides the applied force.”

We need a force to cause motion but we don’t need a force to keep moving. If I push my friend in hockey, he keeps moving since the friction is very small. We also have different kinds of motion. Uniform motion, accelerated motion. To have acceleration, we need to have a net force, but in a uniform motion the net force is zero.

Frank

Force is pushing and motion is moving. You push something and it moves.

Force is in newtons and is the result of pressure. Like applied force. I push you and the result of this pressure is force. Motion is the result of force. I push you and you move. If you don’t move, then there is another force that is against your motion. Like friction. That is why we usually talk about a net force in physics.”

Gabriella

An object in motion has speed. If a kind of force is exerted on an object, the speed will change.

I know more about force and motion now. A force can change the direction of motion and also the speed of an object. This is what Newton’s second law is about. The relationship between force and acceleration and there is an acceleration when the velocity changes.