Potential vs. Kinetic Energy
A skateboarder rolls down a ramp and speeds up. What type of energy is increasing?
Answer: Kinetic energy
Two students push a box in opposite directions with equal force. What is the net force?
Answer: Zero — the forces cancel.
If 10 N pulls up and 10 N pulls down, what is the vertical net force?
Answer: 0 N
A toaster warms bread. What type of energy increases in the bread?
Answer: Thermal energy
A car stops when the driver hits the brakes. Which force mainly causes the stop?
Answer: Friction
A book is lifted from the floor to a high shelf. What happens to its gravitational potential energy?
Answer: It increases because its height increases.
A cart speeds up as it rolls down a hill. What does this tell you about the forces?
Answer: There is an unbalanced force acting downhill.
A toy car has 6 N left and 2 N right. What is the net force and direction?
Answer: 4 N left
A windmill spins when the wind blows. What energy transformation occurs?
Answer: Kinetic energy of wind → mechanical energy
A magnet pulls a paperclip across a table. What type of force is this?
Answer: Magnetic force
A stretched rubber band is released. What energy transformation happens?
Answer: Elastic potential energy → kinetic energy
A soccer ball changes direction but keeps the same speed. What changed — speed, direction, or both?
Answer: Direction only.
A floating balloon has 8 N upward lift and 5 N downward gravity. What happens to the balloon?
Answer: It rises upward.
A flashlight turns on. What energy transformation happens?
Answer: Chemical → light (and thermal)
A swimmer pushes water backward to move forward. Which law explains this?
Answer: Newton’s 3rd Law
A diver stands at the edge of a diving board, not moving. Why does she still have potential energy?
Answer: She is elevated above the water.
A tug‑of‑war rope accelerates to the right. Which team is pulling harder?
Answer: The team on the right.
A box has 12 N right, 12 N left, and 5 N upward. What is the net force?
Answer: 5 N upward
A roller coaster climbs a hill using a motor. What energy increases?
Answer: Gravitational potential energy
A satellite orbits Earth. What force keeps it in orbit?
Answer: Gravity
A ball thrown straight up slows down as it rises. What energy transformation is happening?
Answer: Kinetic energy → gravitational potential energy
A box has 20 N pushing right and 5 N pushing left. Describe the motion.
Answer: It accelerates to the right.
A sled has 15 N forward, 10 N backward, and 5 N sideways. Is the net force zero or nonzero?
Answer: Nonzero — forces don’t cancel.
A meteor speeds up as it falls toward Earth. What energy transformation occurs?
Answer: Gravitational potential → kinetic
A student pushes a heavy box but it doesn’t move. Why not?
Answer: Static friction is equal to the applied force.