Physics · Unit 2
Pushes and Pulls
Forces that make things move
A force is an interaction between two things, and the single hardest idea in early physics is that forces come in pairs and that an object at rest usually has several acting on it.
The unit covers what forces do, contact and non-contact forces, gravity, friction and grip, and balanced versus unbalanced forces.
This unit breaks down into 20 short steps and 120 questions, starting at difficulty 1 and building to 2. Below you can see exactly what it covers, how the path is structured, and worked examples with explanations.
- Steps
- 20
- Questions
- 120
- Difficulty
- 1-2
What this unit covers
- What Forces Do
- Balanced and Unbalanced Forces
- Push, Pull and Contact
- Gravity Pulls Down
- Friction and Grip
Where this fits
The foundation for Motion and Speed and for Forces and Newton's Laws.
Where people slip
Balanced forces mean no change in motion, not no motion. A car at a steady sixty has balanced forces on it exactly as a parked one does.
How the unit is structured
Pushes and Pulls runs as 20 short steps that unlock in order. 15 are practice rounds and 5 are challenge rounds that pull together everything before them. Questions start at difficulty 1 and climb to 2 as you progress.
Challenge rounds
Example questions
30 real questions from this unit, with the answer and the reason behind it, grouped by what they practise. There are 120 in the unit altogether.
Balanced and Unbalanced Forces
- Choose all that applyLevel 1
1. Which of these show unbalanced forces, where something starts moving or speeds up?
- A car speeding up when the engine pushes itcorrect
- A sled sliding faster down a snowy hillcorrect
- A book lying still on a table
- A parked car staying in one place
A car speeding up and a sled sliding downhill have unbalanced forces, while resting objects have balanced forces.
- Fact or fibLevel 1
2. Balanced forces can make a parked car suddenly speed up on their own.
Answer: False
Balanced forces keep things still, so it takes unbalanced forces to make a car speed up.
- Fill the blankLevel 1
3. When one team pulls harder in a tug of war, the forces are ____ and the rope moves.
- unbalancedcorrect
- balanced
- equal
- gone
Unequal forces are unbalanced, so the rope moves toward the stronger team.
- Match the pairsLevel 1
4. Match each idea about forces with what it means.
Answer: Balanced forces = an object stays still or steady; Unbalanced forces = an object speeds up or turns; A push and pull that are equal = nothing starts to move; One force bigger than the other = the object moves that way
Balanced forces keep things steady, while unbalanced forces make things move.
- Build the sentenceLevel 2
5. Build the rule about what balanced forces do.
Answer: balanced forces do not change motion
Balanced forces have a zero resultant, so they do not change an object's motion.
- Guess the numberLevel 2
6. A trolley has a 10 N force pushing right and a 4 N force pushing left. What is the size of the resultant force?
Answer: 6 N
The forces oppose, so 10 N - 4 N = 6 N acting to the right.
Friction and Grip
- Match the pairsLevel 1
7. Match each situation with what friction does.
Answer: Rubbing your hands together = makes them feel warm; Bike brakes squeezing the wheel = make the bike slow down; Rubber soles on shoes = grip the pavement well; A puddle of oil on the floor = makes it very slippery
Friction can warm things up, slow bikes down, grip shoes, and oil removes it to make surfaces slippery.
- Multiple choiceLevel 1
8. What does friction do to a ball rolling across the floor?
- Slows it down until it stopscorrect
- Makes it roll forever
- Makes it change colour
- Lifts it into the air
Friction slows the rolling ball down until it stops.
- Choose all that applyLevel 2
9. Which of these increase the friction acting on a sliding object? Choose all that apply.
- Using a rougher surfacecorrect
- Pressing the surfaces together hardercorrect
- Spreading oil between them
- Fitting a deep tread patterncorrect
Rougher surfaces, more tread, and pressing harder all raise friction, while oil lowers it.
- Fact or fibLevel 2
10. Adding oil between two metal parts reduces the friction between them.
Answer: True
Oil is a lubricant that keeps surfaces apart, lowering the friction and wear.
- Fill the blankLevel 2
11. Air resistance is a kind of friction that acts through the air and is also called ____.
- dragcorrect
- thrust
- upthrust
- tension
Air resistance, or drag, is a frictional force from air that opposes moving objects.
- Guess the numberLevel 2
12. A car engine drives it forward with 500 N while friction and air resistance push back with 200 N. What is the resultant force on the car?
Answer: 300 N
The resultant is the forward force minus the backward force, so 500 N minus 200 N gives 300 N forward.
Gravity Pulls Down
- Build the sentenceLevel 1
13. Put the words in order to make a true sentence about gravity.
Answer: Gravity pulls everything down to the ground
Gravity pulls everything down to the ground.
- Fill the blankLevel 1
14. Gravity always pulls objects ____.
- downcorrect
- up
- sideways
- backwards
On Earth, gravity always pulls objects downward.
- Multiple choiceLevel 1
15. Which way does gravity pull objects on Earth?
- Down toward the groundcorrect
- Up into the sky
- Sideways to the left
- Round and round in circles
Gravity pulls everything down toward the ground.
- Fact or fibLevel 2
16. In a vacuum with no air, a feather and a hammer fall and land at the same time.
Answer: True
Without air resistance, gravity accelerates all objects at the same rate regardless of mass.
- Guess the numberLevel 2
17. On Earth (g = 9.8 N/kg), what is the weight of a 5 kg bag? Use weight = mass x g.
Answer: 49 N
Weight = mass x g = 5 x 9.8 = 49 N.
- Match the pairsLevel 2
18. Match each quantity to the unit it is measured in.
Answer: Weight = newton (N); Mass = kilogram (kg); Gravitational field strength = N/kg; Free-fall acceleration = m/s^2
Weight is a force in newtons, while mass is in kilograms and g is in N/kg.
Push, Pull and Contact
- Build the sentenceLevel 1
19. Put the words in order to make a true sentence about pulling.
Answer: A pull brings an object closer to you
A pull brings an object closer to you.
- Fill the blankLevel 1
20. A ____ force only works when it touches the object.
- contactcorrect
- gravity
- magnetic
- distant
A contact force, like a push or pull, needs to touch the object to act on it.
- Choose all that applyLevel 2
21. Select every force below that is a contact force.
- Frictioncorrect
- Tension in a ropecorrect
- The normal reaction from a tablecorrect
- Gravity
Friction, tension, and the normal reaction all need surfaces or objects touching, while gravity acts at a distance without contact.
- Fact or fibLevel 2
22. A magnet attracting a paperclip across a small gap is a contact force.
Answer: False
Magnetism acts at a distance without touching, so it is a non-contact force.
- Guess the numberLevel 2
23. A spring has a spring constant of 50 N/m. What force is needed to stretch it by 0.20 m? (use F = k x)
Answer: 10 N
By Hooke's law force equals spring constant times extension, so 50 N/m times 0.20 m gives 10 N.
- Match the pairsLevel 2
24. Match each force to what it does.
Answer: Tension = Pull along a rope; Friction = Opposes sliding; Normal force = Push up from a surface; Upthrust = Push up from a liquid
Each contact force acts in a specific way where two objects or a fluid touch.
What Forces Do
- Fact or fibLevel 1
25. A force is only ever a push and never a pull.
Answer: False
A force can be either a push or a pull, so this is false.
- Multiple choiceLevel 1
26. What is a force?
- A push or a pullcorrect
- A type of colour
- A kind of sound
- A special shape
A force is simply a push or a pull on an object.
- Choose all that applyLevel 2
27. Which statements about force are true? Choose all that apply.
- It is measured in newtonscorrect
- It has both a size and a directioncorrect
- It is measured in kilograms
- It can be drawn as an arrowcorrect
Force is a vector measured in newtons with size and direction, often drawn as an arrow.
- Fill the blankLevel 2
28. A single force that has the same effect as all the forces on an object is called the ____ force.
- resultantcorrect
- contact
- magnetic
- elastic
The resultant force is the single overall force found by combining all the forces.
- Guess the numberLevel 2
29. A 9 N force pulls right and a 4 N force pulls left on the same object. What is the size of the resultant force?
Answer: 5 N
Opposite forces subtract, so 9 N - 4 N = 5 N acting to the right.
- Odd one outLevel 2
30. Three of these are effects a force can have. Which one is the odd one out?
- Make an object speed up
- Make an object change direction
- Change an object's shape
- Change an object's colourcorrect
Forces change motion, direction, and shape, but they do not change an object's colour.
Where these questions come from. Each unit starts as a plan of the concepts it should cover and the difficulty it should span. Questions are written against that plan with AI assistance, then checked by a validator that rejects anything without a single defensible answer, an explanation, or plausible wrong options. How we write questions sets out the whole process, and corrections are fixed in the bank and reach the site and the app the same day.
How you practise
This unit mixes 17 different question formats, so you are recalling and applying rather than recognising the same layout every time.
- Build the sentence
- Choose all that apply
- Fact or fib
- Fill the blank
- Guess the number
- Listen and choose
- Match the pairs
- Multiple choice
- Odd one out
- Picture question
- Put in order
- Sequence recall
- Sort into groups
- Spell it
- Tap the pairs
- True or false
- Type the answer
Practise Pushes and Pulls
120 questions across 20 steps. Start with step one and crawl at your own pace.
Play this unitRead about Pushes and Pulls
Explainers from our blog on what this unit covers. Each one ends with real questions from the bank.
More units in Physics
- What is Physics?The science of how the world works
- Motion and SpeedHow things move
- Simple MachinesTools that make work easier
- States of Matter and DensitySolids, liquids, gases and more
- Energy and Its FormsThe power to make things happen
- Light and SoundSeeing and hearing the world
- Electricity and MagnetsSparks, circuits and magnets
- Measurement and UnitsMeasuring the physical world