Forces Flashcards
A = (v-u) ➗ t
Acceleration =
change in velocity ➗time taken
F = ma
Force = mass x acceleration
Acceleration
The rate at which objects changed their velocity
Resultant force
An unbalanced force
The overall force acting on an object
Gravity
The magnetic pull from the centre of the earth
W = m x g
Weight (N) = mass of an object x acceleration due to gravity (m/s2)
Friction
Energy changes
When occurs
Causes moving objects to slow down and finally stop. The kinetic energy of the moving object is converted to heat as work is done by the engine force Occurs when (solid) objects run against other objects & when object move through fluids
Air resistance
A friction force which opposes the movement of an object moving through the air
Drag
Air resistance
The size of the drag force acting on an object depends on its shape & speed
The force that keeps an object in the air
Lift
Carries something upwards in spite of gravity eg the upward push of the surrounding air on a balloon
Also acts on objects immersed in liquids
Upthrust
Terminal velocity
When something is still falling but it won’t get any faster because the drag force on the object balances it’s weight
When will the friction force acting between the road n the tyres of a vehicle be at it’s maximum
Tyres have good tread n properly inflated
Road is dry
Vehicle is heavy
Stopping distance
The sum of the thinking distance and the braking distance
Thinking distance
The time before the brakes are applied
