PRE-IGCSE SCIENCE (KS3) EXAM 2025
QUESTIONS AND ANSWERS
What can forces do? - ANS Forces can:
change the shape or size of an object
change the speed things are moving (make them move faster or slower)
change the direction of a moving object.
What are forces? - ANS Forces are pushes or pulls.
What are forces measured in and by? - ANS The units for measuring force are newtons (N).
We can use Newton meters to measure forces.
List some contact forces. - ANS friction
air resistance
water resistance
upthrust.
List some non contact forces - ANS magnetism
gravity
static electricity.
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,What is Newton's third law of motion? - ANS Every force has an equal but opposite reaction
force.
(Forces come in pairs).
What is friction? - ANS Friction is a force caused by two things rubbing together.
It acts in the opposite direction to movement.
What does friction do? - ANS Friction slows moving things down.
Friction can wear things away.
Friction can stop things sliding/moving.
Friction releases heat and noise.
What surfaces have the most friction? - ANS Rough surfaces
How can you reduce friction? - ANS Use lubrication / oils.
What is drag? - ANS A force that acts against an object when it is moving through water or
air.
Air resistance is an example of drag.
What does drag do? - ANS Drag slows moving things down.
How can you reduce drag? - ANS Make objects streamlined.
Why do dense objects sink? - ANS Their force of weight is greater than the force of upthrust
(unbalanced forces).
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, Why do less dense objects float? - ANS The force of weight is equal to the force of upthrust
(they are balanced forces).
What is Newton's 1st Law? - ANS When the forces acting on an object are balanced, it will
remain at rest (stationary) or continue in a straight line at the same speed.
If the forces acting on an object are unbalanced it can change speed, direction or shape.
What is density? - ANS The amount of mass (stuff) in a given volume.
Describe how the forces change when a spring is stretching. - ANS The force of weight acting
down is bigger than the reaction force acting upwards. (They are unbalanced)
The spring stretches and the reaction force gets bigger.
Eventually the reaction force equals the weight force (they balance) and the spring stops
stretching.
What are the rules of drawing force diagrams? - ANS The size of the arrow represents the
size of the force (big arrow = big force / small arrow = small force).
The direction of the arrow shows the direction of the force.
Every arrow should be labelled with the force.
e.g.
What is weight? - ANS Weight is the force due to gravity.
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QUESTIONS AND ANSWERS
What can forces do? - ANS Forces can:
change the shape or size of an object
change the speed things are moving (make them move faster or slower)
change the direction of a moving object.
What are forces? - ANS Forces are pushes or pulls.
What are forces measured in and by? - ANS The units for measuring force are newtons (N).
We can use Newton meters to measure forces.
List some contact forces. - ANS friction
air resistance
water resistance
upthrust.
List some non contact forces - ANS magnetism
gravity
static electricity.
COPYRIGHT © 2025 BRAINBARTER ALL RIGHTS RESERVED 1
,What is Newton's third law of motion? - ANS Every force has an equal but opposite reaction
force.
(Forces come in pairs).
What is friction? - ANS Friction is a force caused by two things rubbing together.
It acts in the opposite direction to movement.
What does friction do? - ANS Friction slows moving things down.
Friction can wear things away.
Friction can stop things sliding/moving.
Friction releases heat and noise.
What surfaces have the most friction? - ANS Rough surfaces
How can you reduce friction? - ANS Use lubrication / oils.
What is drag? - ANS A force that acts against an object when it is moving through water or
air.
Air resistance is an example of drag.
What does drag do? - ANS Drag slows moving things down.
How can you reduce drag? - ANS Make objects streamlined.
Why do dense objects sink? - ANS Their force of weight is greater than the force of upthrust
(unbalanced forces).
COPYRIGHT © 2025 BRAINBARTER ALL RIGHTS RESERVED 2
, Why do less dense objects float? - ANS The force of weight is equal to the force of upthrust
(they are balanced forces).
What is Newton's 1st Law? - ANS When the forces acting on an object are balanced, it will
remain at rest (stationary) or continue in a straight line at the same speed.
If the forces acting on an object are unbalanced it can change speed, direction or shape.
What is density? - ANS The amount of mass (stuff) in a given volume.
Describe how the forces change when a spring is stretching. - ANS The force of weight acting
down is bigger than the reaction force acting upwards. (They are unbalanced)
The spring stretches and the reaction force gets bigger.
Eventually the reaction force equals the weight force (they balance) and the spring stops
stretching.
What are the rules of drawing force diagrams? - ANS The size of the arrow represents the
size of the force (big arrow = big force / small arrow = small force).
The direction of the arrow shows the direction of the force.
Every arrow should be labelled with the force.
e.g.
What is weight? - ANS Weight is the force due to gravity.
COPYRIGHT © 2025 BRAINBARTER ALL RIGHTS RESERVED 3
