Cell biology flash cards
Flash cards on cell structure, organelles, plant and animal cells, bacteria, diffusion, osmosis, active transport, mitosis and microscopy for school biology.
Flash card deck23 cardsIntermediateSchool
Forces and motion flash cards (Newton's laws)
Flash cards on forces and motion: Newton's three laws, F = ma, weight, resultant force, speed, velocity, acceleration, motion graphs, momentum and stopping distance.
Free to use, edit, print and study. No account needed: your set stays on this device.
The cards, front and back
- 1Front
What is a force?
BackA push or a pull on an object caused by an interaction with another object. It is measured in newtons (N) and has both size and direction.
- 2Front
Scalar and vector quantities
BackA scalar has size (magnitude) only, such as speed, distance, mass and energy. A vector has size and direction, such as velocity, displacement, force and acceleration.
- 3Front
Newton's first law
BackAn object stays at rest, or keeps moving at a constant speed in a straight line, unless a resultant force acts on it.
- 4Front
Newton's second law
BackThe acceleration of an object is proportional to the resultant force on it and inversely proportional to its mass: F = ma.
- 5Front
Newton's third law
BackWhen two objects interact, they exert equal and opposite forces on each other. The two forces act on different objects and are the same type of force.
- 6Front
What is inertia?
BackThe tendency of an object to stay at rest or keep moving at the same velocity. The more mass an object has, the more inertia it has.
- 7Front
What is a resultant force?
BackThe single force that has the same effect as all the forces acting on an object combined. If the forces are balanced, the resultant force is zero.
- 8Front
A 1200 kg car accelerates at 2 m/s². What is the resultant force?
BackF = ma = 1200 × 2 = 2400 N.
- 9Front
Mass and weight
BackMass is the amount of matter in an object, in kilograms, and does not change with location. Weight is the force of gravity on that mass, in newtons: W = mg.
- 10Front
What is the gravitational field strength on Earth?
BackAbout 9.8 N/kg (often rounded to 10 N/kg in school questions). So a 50 kg person weighs about 490 N.
- 11Front
Speed, distance and time
BackSpeed = distance ÷ time. Speed is measured in metres per second (m/s).
- 12Front
Speed and velocity
BackSpeed is how fast something moves. Velocity is speed in a given direction, so an object moving in a circle at a steady speed has a changing velocity.
- 13Front
What is acceleration?
BackThe rate of change of velocity: a = (v − u) ÷ t, measured in metres per second squared (m/s²). A negative acceleration is a deceleration.
- 14Front
What does the gradient of a distance–time graph show?
BackThe speed. A horizontal line means the object is stationary, and a steeper line means a higher speed.
- 15Front
What does a velocity–time graph show?
BackThe gradient gives the acceleration, and the area under the line gives the distance travelled.
- 16Front
Equations of motion for constant acceleration
Backv = u + at and v² = u² + 2as, where u is initial velocity, v final velocity, a acceleration, t time and s displacement.
- 17Front
What is friction?
BackA force that opposes motion when two surfaces move, or try to move, past each other. Air resistance and drag are types of friction in fluids.
- 18Front
What is terminal velocity?
BackThe steady top speed reached by a falling object when air resistance has grown to equal its weight, so the resultant force is zero.
- 19Front
What is momentum?
BackMomentum = mass × velocity (p = mv), measured in kg m/s. It is a vector.
- 20Front
What is conservation of momentum?
BackIn a closed system, the total momentum before a collision or explosion equals the total momentum after it.
- 21Front
What makes up stopping distance?
BackStopping distance = thinking distance + braking distance. Tiredness, alcohol and distractions increase thinking distance. Speed, wet or icy roads and worn tyres or brakes increase braking distance.
- 22Front
What is the moment of a force?
BackThe turning effect of a force: moment = force × perpendicular distance from the pivot, in newton metres (N m).
- 23Front
What is Hooke's law?
BackThe extension of a spring is directly proportional to the force applied, up to the limit of proportionality: F = ke, where k is the spring constant.
How to use this template
This deck covers forces and motion, with Newton's three laws at the centre. It includes scalars and vectors, resultant forces, inertia, F = ma with a worked example, mass and weight, speed, velocity and acceleration, distance–time and velocity–time graphs, the equations of motion for constant acceleration, friction and terminal velocity, momentum and its conservation, stopping distances, moments and Hooke's law. It suits GCSE and IGCSE physics or combined science, Year 9 to Year 11 science, high school physics and a refresher for AP Physics 1, IB physics or first-year mechanics. Learn the laws and equations with Learn mode, then use Test mode and spaced repetition. Print it double-sided to test a classmate.
Tips
- For each equation, learn the units of every quantity at the same time. Many marks are lost by writing the wrong unit.
- When you use Newton's third law, check that the two forces act on different objects. If they act on the same object, they are not a third law pair.
- Draw a free-body diagram for every forces question, with an arrow for each force, before you calculate anything.
- Practise reading motion graphs by saying aloud what each section shows: stationary, constant speed, speeding up or slowing down.
- Convert units first: grams to kilograms, kilometres per hour to metres per second, minutes to seconds.
Make it fit
- Use the value of g your course gives, 9.8 or 9.81 or 10 N/kg, and update the weight card to match.
- Add work done (W = Fd), pressure or circular motion if your course includes them.
- Make a separate equations deck with the word form on the front and the symbol form on the back.
- Add cards for required practicals, such as investigating acceleration with a trolley and light gates.
Updated October 28, 2026