P8 Forces Flashcards
Scalar
A quantity with only magnitude and a unit
Vector
A quantity with magnitude, direction, and a unit
Magnitude
The size of something
Distance
How far an object has travelled. It is a scalar quantity
Displacement
How far away an object is from where it started and in which direction. It is a vector quantity
What can a force do to an object?
- Change the speed
- Change the direction
- Change the shape
Contact Forces
Where contact is required to exert force on an object
Non-contact Forces
A force is exerted from a distance
Friction
The force between two surfaces that are sliding, or trying to slide across, each other
Upthurst
The force of a liquid pushing up against a solid placed in the liquid
Tension/compression
Forces squashing or stretching an object
Air resistance
The effect of air on a moving object
Gravity (weight)
Non-contact force acting between objects with mass
Electrostatic
Force of attraction or repulsion between charged objects
Magnetism
Force of attraction or repulsion in a magnetic field
Newton’s third law of motion
Whenever two objects interact, the forces they exert on each other are equal in size and opposite in direction
Action force
The force acting in one direction from an object
Reaction force
The force acting in the opposite direction from a second object
Circular orbits
The Sun’s gravity pulls in planets but planets have their velocities, therefore it stay in orbit
Centripetal force
Acting towards the centre of a circle
What would happen if a satellite was launched too fast?
It will fly off into space
What would happen if a satellite was launched too slow?
It will fall to the surface
What would happen if a satellite was launched at the correct speed?
It will travel in a circular orbit at a constant height and constant speed
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