Forces: Friction and Gravity — Answers
Answer sheet with model answers and success criteria for the 4th Grade forces & motion worksheet.
Success TutoringWorksheetsAnswer sheet4th Grade · Science · Forces & MotionForces: Friction and Gravity — Answers
Part A: Two important forces
Read the passage. Then circle the best answer.
Friction is a force that happens when two surfaces rub or slide against each other. It acts against movement and slows things down. Rough surfaces usually make more friction than smooth surfaces.
Friction can be helpful: it lets our shoes grip the ground and helps bikes stop when we use the brakes. It can also be a nuisance: it slows down things we want to keep moving.
Gravity is a force that pulls objects towards the Earth. It is why a dropped ball falls to the ground and why things have weight. Gravity pulls on everything, big or small.
Air resistance is a kind of friction from the air. It slows down things moving through the air, like a falling leaf or a parachute.
- Asmooth tiles
- Bice
- Ccarpet
- Dpolished wood
Answer: carpet
Carpet is rough and soft, so there is more friction. The car slows down quickly.
- AFriction pulls you down.
- BGravity pulls you towards the Earth.
- CAir pushes you down.
- DYour legs get tired.
Answer: Gravity pulls you towards the Earth.
Gravity is a pulling force. It pulls everything towards the Earth.
- AIce has very little friction.
- BIce has lots of friction.
- CGravity is stronger on ice.
- DIce pushes your feet up.
Answer: Ice has very little friction.
Ice is very smooth, so there is very little friction to grip your shoes.
- AThey make the bike lighter.
- BThey turn off gravity.
- CThey make the tires look nice.
- DThey give more grip (friction) on the road.
Answer: They give more grip (friction) on the road.
Grooves and bumps give more friction, so the tires grip and do not skid easily.
Part B: Name the force
- an apple falling from a tree
- rubbing your hands together to warm them
- a parachute floating down slowly
- friction
- air resistance
- gravity
Answer: an apple falling from a tree → gravity; rubbing your hands together to warm them → friction; a parachute floating down slowly → air resistance
Answer: slows
Answer: towards
Part C: True or false?
Write True or False.
Answer: False
Gravity pulls on all objects, heavy or light.
Answer: True
Rough surfaces catch and rub against each other more.
Answer: False
Friction helps us walk without slipping and helps brakes stop a bike.
Answer: True
The big parachute pushes against lots of air, which slows it down.
Part D: Working scientifically: the ramp test
Help Leo plan a fair test. You can try it at home too.
Leo makes a ramp from a large book and a piece of stiff cardboard. He lets a toy car roll down the ramp onto three different surfaces: thick carpet, smooth tiles and a wooden floor.
Answer: The surface the car rolls onto (thick carpet, smooth tiles or a wooden floor).
Answer: Any two of: the same car, the same ramp, the same ramp height, letting go from the same starting point without pushing, measuring the same way.
Answer: How far the car rolls from the bottom of the ramp before it stops.
Model answer: I predict the car will roll the shortest distance on the thick carpet, because it is the roughest surface. It makes the most friction, so the car slows down and stops sooner.
Success criteria:
- Makes a clear prediction
- Links rougher surfaces to more friction
- Says more friction slows the car down
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.
Great work. Here's what to try next: