Design an Experiment
Students test whether a stronger push makes a toy car travel farther. What's the dependent variable.
The distance the car travels.
A book rests on a desk without moving. Are the forces balanced or unbalanced?
Balanced
You push a toy car forward, and it starts moving. Which direction does it travel?
Forward.
What type of force do you apply when you shove a chair away from you?
A push.
What transfers from your hand to a toy when you push it and make it move?
Energy.
Students test whether the strength of a kick affects how far a soccer ball travels. What is the independent variable?
Strength of kicks.
Two students push opposite sides of a box with the same amount of force. Are their forces equal or unequal?
Equal
Two students push a supply cart toward the classroom door. Do their pushes work together or against each other?
Together, because they push in the same direction.
What type of force do you apply when playing tug of war.
Pull.
A moving marble hits a resting marble, which begins rolling. Identify where energy transfers.
From the moving marble to the resting marble.
Students slide a block across tile and carpet to compare friction. Name two things they should keep the same.
The block and the strength of the starting push
A toy truck is sitting still. Someone pushes it, and it begins rolling. Were the forces balanced or unbalanced when it started moving?
Unbalanced.
One student pushes a box right with 12 newtons of force. Another pushes left with 7 newtons. If the box starts moving, which direction will it move?
Right, toward the stronger push.
A student tosses a ball straight up. It slows down, stops for a moment, and falls back down. Which force causes these changes?
A rolling toy car hits a block. The block slides, and the car slows down. What evidence shows energy transferred?
The block begins moving after the collision.
A group tests whether a stronger magnet attracts more paper clips. They give one magnet 10 paper clips and another magnet 20. Why is this unfair? How should they fix it?
They used different numbers of paper clips. Each magnet should get the same number.
A student says, “Balanced forces always make an object stop.” Explain the mistake.
Balanced forces do not change motion. A resting object stays still. A moving object keeps the same speed and direction.
Two students pull opposite ends of a rope with 20 newtons each. The rope starts at rest. Will these pulls make it move? Explain.
No. The pulls are equal and opposite, so they balance.
A toy car rolls across a smooth floor and then onto a rough carpet. It slows down and stops. Explain which force changes its motion.
Friction.
A student hits a hockey puck with a stick, making it move. Where does the puck get the energy to start moving?
Energy transfers from the stick to the puck when the stick hits it.
Design a fair test to find out whether a stronger push makes a swing travel higher. Explain what your independent variable is, dependent variable, and 2 controls.
independent varible: stength of push.
Dependent varible: height of swing
at least 2 controls: could be use the same swing, same rider in swing, and same starting position.
A rolling skateboard speeds up. Later, it slows down and comes to a stop. Describe the forces during each part.
The forces are unbalanced while it speeds up and while it slows down. Once it stays stopped, the forces are balanced.
Two students push a cart right with 8 newtons each. A third student pushes left with 12 newtons. Which direction is the overall force? Explain.
Right. The rightward pushes total 16 newtons, which is greater than 12 newtons left.
Name three ways an unbalanced force changes the motion of a moving object.
It speeds up, slows down, or changes direction.
A moving bowling ball hits resting pins. Explain the energy transfer and why the pins’ motion changes.
Energy transfers from the ball to the pins. The ball applies an unbalanced force, making the pins move.