A moving sidewalk at the airport moves about 1 m/s relative to the ground around it. If you walk at a speed of 2 m/s relative to the sidewalk, how fast are you moving relative to the ground?

If a ball is accelerated downward at 9.8 m/s², by how many meters per second does the object's velocity change every second?

Two balls are released from the same height. One is dropped and the other is horizontally launched. Why do they reach the ground at the same time?

If an object is being pulled by two forces, one 4 N to the left and the other 2 N to the right, what is the net force acting on the object? Draw the free body diagram for this situation.

1. A box is being pulled across a horizontal surface by a 20 N force to the right.
   1. If the box moves at a constant velocity, what do you know about the forces acting on the object?
   2. If the box moves at a constant velocity, how much force opposes the motion of the box?
   3. If the box experiences a force of 15 N to the left, along with the 20 N force acting to the right, what is the net force on the box?

A 1000 kg elevator is accelerated upward at a rate of 0.70 m/s2. What is the tension in the cable pulling the elevator upward when it experiences this acceleration? Be sure to draw a free-body diagram.

A 25 kg sled is pulled across a horizontal surface by a 200 N force at a constant velocity. What is the coefficient of friction between the sled and the surface?

A 2 kg falling object experiences 5 N of air resistance. What is the acceleration of this object?

What is the force of tension in a rope that spins a 250 g object in a vertical circle with a radius of 50 cm if the mass at the top of the loop is traveling at 3 m/s?

A woman stands in a boat at rest on a calm lake. She throws a 10 kg anchor off the front of the boat, which has a mass of 1,000 kg.

1. What is the initial momentum of the anchor-boat system?
2. In which direction will the boat move after the anchor is thrown?
3. How does the change in momentum of the anchor compare to the change in momentum of the boat?
4. If the velocity of the anchor is 12 m/s, what is the velocity of the boat after the anchor is released?
5. A 4 kg bowling ball rolls at 8 m/s to the right and strikes a 6 kg bowling ball that is rolling at 2 m/s to the left. If the 4 kg ball bounces back with a velocity of 4 m/s to the left, what is the velocity of the 6 kg ball after the collision?

Ben lifts a 50 N block 2 m. If the net work done on the block is 50 J, what is the applied force on the block?

A 1.5 kg block moves at 4 m/s moves along a frictionless horizontal surface. The block slides into a spring with a spring constant of 240 N/m. How far is the spring compressed after the block comes to rest?

A 100 g car at rest rolls down a frictionless incline from a starting height of 0.50m.

1. What is the final velocity of the car?
2. Assuming the surface is not frictionless, and the final velocity of the car in the previous question is only 1 m/s, how much energy is lost due to friction?