Push or Pull
You open a door toward you. What is the force?
Pull
What is friction?
A force that happens when surfaces rub together.
Two people push a box equally from opposite sides. What happens?
Balanced forces; it does not move
Why don’t you slip when you walk?
Friction between shoes and ground
Name a force and tell if it’s a push or pull.
Answers will vary.
A push is when you move something away from you.
Pushing a shopping cart at the store.
A pull is when you bring something toward you.
Pulling a wagon.
You push a shopping cart. What type of force is this?
Push
Does friction help or hurt when walking?
Helps (prevents slipping)
What do balanced forces do?
Cancel out; no movement
Why does a sled slow down?
Friction
Give one example of friction and explain it.
Answers will vary.
Rubbing your hands together - When you rub your hands, they feel warm. That’s because friction is creating heat as your hands move against each other.
Lifting a backpack off the floor—is it a push or pull?
Pull
Why do bike brakes work?
Friction slows/stops the wheel
What do unbalanced forces do?
Cause movement
Why do car tires need tread?
To increase friction/grip
Give one helpful AND one harmful example of friction.
Answers will vary.
Helpful friction - Shoes gripping the ground.
Friction helps you not slip when you walk or run.
Harmful friction - Getting a scrape on your knee
Friction between your skin and the ground can hurt you and cause a scrape.
Closing a drawer—push or pull? Explain.
Push, moving it away from you into place)
Why do we add oil to machines?
To reduce friction
A ball starts rolling after being kicked. Balanced or unbalanced?
Unbalanced
Why is it harder to push a desk on carpet than tile?
More friction
Why does a moving object stop if no one touches it?
Friction slows it down
A force moves an object away from you. What type of force is it AND why?
Push, because it moves something away
Explain how friction can BOTH help and harm.
Helps (walking, stopping); harms (wears things down, slows motion)
Explain the difference between balanced and unbalanced forces with examples.
Balanced = no movement; unbalanced = movement
Give a real-life example of friction helping AND explain why.
Answers will vary.
Explain how forces and friction work together to affect motion.
Answers will vary.
Forces move objects; friction resists motion and can slow/stop them