Contact vs Non-Contact Forces
What type of force requires objects to touch?
Contact force
What force slows down moving objects when they rub together?
Friction
What force supports an object resting on a surface?
Normal force
What force pulls iron objects toward a magnet?
Magnetic force
What force pulls objects toward the Earth?
Gravitational force
What type of force acts without touching?
Non-contact force
Does friction increase or decrease motion?
Decrease
In which direction does the normal force act?
Upward (perpendicular to the surface)
Do like magnetic poles attract or repel?
repel
What happens to a ball when you drop it?
It falls down
Give one example of a contact force.
Friction / Normal / Spring force
Which surface has more friction: rough or smooth?
Rough surface
What force is produced when a spring is stretched or compressed?
Spring force
What force causes a rubbed balloon to stick to a wall?
Electrostatic force
Does gravity act only on Earth?
No
Give one example of a non-contact force.
Gravitational / Magnetic / Electrostatic force
Give one example where friction is useful.
Walking / Braking / Writing
What happens to spring force when you stretch a spring more?
It increases
Do opposite electric charges attract or repel?
Attract
Which has stronger gravity: a small object or a large planet?
Large planet
Why is gravitational force called a non-contact force?
It acts at a distance without touching objects
Why do we put oil on machine parts?
To reduce friction
Why does a stretched spring return to its original shape?
Because of restoring (spring) force
What do magnetic and electrostatic forces have in common?
They are non-contact forces
Why do planets stay in orbit around the Sun?
Because of gravitational force