Forces And Motion Flashcards
What is velocity
Velocity is how fast you’re going but must also have the direction specified
What is acceleration
How quickly the velocity is changing ( how quickly you’re speeding up)
Acceleration formula
Acceleration= Change in velocity/ time taken
What is the difference between weight and mass
Mass is just the amount of stuff In an object
Weight is caused by the pull of gravity. The weight of an object is just the force of gravity pulling an object down towards earth
Formula for mass
Weight= mass x gravitational field strength
First law of motion
Balanced forces mean no change in velocity.
As long as the forces of an object are all balanced, then it’ll just stay still or else if it’s already moving it’ll just carry on at the same velocity- so long as the forces are all balanced
Example of the first law of motion
When a bus is moving at constant velocity then the forces on it must all be balanced
What must there be to keep going at a steady speed
To keep going at a steady speed there must be zero resultant force
Second law of motion
A resultant force means acceleration
If there is an unbalanced force, then the object will accelerate in that direction
The bigger the force,
The greater the acceleration or celebration
The bigger the mass,
The smaller the acceleration
Resultant force equation
Resultant force= Mass x acceleration
What is speed
Speed is just how fast you’re going with no regard to the direction
The Third law
If object A exerts a force on object B then object B exerts the exact opposite force on object A
E.g. If you push a shopping trolley it will push back against you just as hard
What is friction
Something that occurs between two surfaces in contact, friction always acts in the opposite direction of movement
What is work done
Work done is energy transferred.
When a force moves an object, energy is transferred and work is done
Work done= force x distance
What is kinetic energy
Energy of movement
What does kinetic energy depend on
Mass and speed, the greater an objects mass and the faster it’s going, the bigger its kinetic energy will be
What is the equation for kinetic energy
Kinetic energy = 1/2 x mass x velocity2(squared)
What is elastic potential energy
The energy stored when work is done on an object to change its shape.
Springs store elastic potential energy whenever they’re compressed or stretched
What is gravitational potential energy
Gravitational potential energy is the energy stored in an object when you raise it to a height against gravity
