Newton's First and Third Laws Answers

A car is moving east along a straight, level road at a constant velocity. Which forces form an action/reaction force pair?

Which statements describe an object in motion that has no external force acting on it? Check all that apply.It accelerates and speeds up.It moves at a constant speed.It decelerates and slows down.It changes direction.It moves in the same direction.

Which is an action/reaction force pair? Check all that apply.Earth pulls on a book, and the book pushes against a shelf.A hockey stick hits a puck, and the puck pushes against the stick. A pencil pushes against a piece of paper, and the paper pushes against the desk.A finger pulls on a rubber band, and the rubber band pushes against the finger.A dog pulls on a leash, and the owner pulls back on the leash.

Which best describes the forces identified by Newton’s third law of motion?

A box is sitting on the floor. The box was then pulled with a force, Ft. The box did not move. The free-body diagram of the box is shown.

A ball strikes a wall. It exerts a force of 10 N to the left against the wall and bounces off. What force does the wall exert on the ball?

Which object is in static equilibrium?

Keisha writes that if an object has any external forces acting on it, then the object can be in dynamic equilibrium but not static equilibrium.Which statement best describes Keisha’s error?

Kamala puts on inline skates and stands facing a wall. When she pushes against the wall, she rolls backward.Why does pushing harder make her roll faster?

Lien is pushing a box across a table. She used a force of 100 N to get the box moving. Which force did she overcome to get the box moving?