OCR A Level Physics Module 1-3
Displacement - The distance travelled in a particular direction from a fixed
origin
Velocity - Rate of change of displacement
Scalar - A quantity that has magnitude but not direction
Vector - A quantity that has both magnitude and direction
Acceleration - Rate of change of velocity
Newton's First Law - An object will remain at rest or in a state of uniform
motion unless it is acted on by an external unbalanced force
Newton's Second Law (simple) - The unbalanced force, mass and
acceleration of an object are related by the equation F=ma
Newton's Third Law - When two objects interact, they exert equal and
opposite forces on each other.
Newton (N) - The force required to give a mass of 1kg an acceleration of 1m/s
in the direction of the force
Centre of Gravity - The point where the entire weight of an object appears to
act
Couple - A pair of forces that tend to produce rotation only. They must be
equal and opposite
, OCR A Level Physics Module 1-3
Torque - Turning effect of a couple. One of the forces x perpendicular
distance between the forces
Moment - Turning effect of a force. Force x perpendicular distance between
the force and the pivot
Equilibrium - Both the net force and net moment on the object must be zero
Principle of Moments - For an object in equilibrium, sum of clockwise
moments must equal the sum of the clockwise moments.
Density - Mass per unit volume
Pressure - Force per unit area
Thinking distance - Distance travelled by the car in the time taken by the
driver to react
Braking distance - Distance travelled by the car when the brakes are applied
and the car stops
Stopping distance - Sum of thinking distance and braking distance
Braking force - Frictional force applied by the road on the tyre in the opposite
direction to motion which causes the vehicle to come to rest
Work done - Force x distance moved in the direction of the force
Displacement - The distance travelled in a particular direction from a fixed
origin
Velocity - Rate of change of displacement
Scalar - A quantity that has magnitude but not direction
Vector - A quantity that has both magnitude and direction
Acceleration - Rate of change of velocity
Newton's First Law - An object will remain at rest or in a state of uniform
motion unless it is acted on by an external unbalanced force
Newton's Second Law (simple) - The unbalanced force, mass and
acceleration of an object are related by the equation F=ma
Newton's Third Law - When two objects interact, they exert equal and
opposite forces on each other.
Newton (N) - The force required to give a mass of 1kg an acceleration of 1m/s
in the direction of the force
Centre of Gravity - The point where the entire weight of an object appears to
act
Couple - A pair of forces that tend to produce rotation only. They must be
equal and opposite
, OCR A Level Physics Module 1-3
Torque - Turning effect of a couple. One of the forces x perpendicular
distance between the forces
Moment - Turning effect of a force. Force x perpendicular distance between
the force and the pivot
Equilibrium - Both the net force and net moment on the object must be zero
Principle of Moments - For an object in equilibrium, sum of clockwise
moments must equal the sum of the clockwise moments.
Density - Mass per unit volume
Pressure - Force per unit area
Thinking distance - Distance travelled by the car in the time taken by the
driver to react
Braking distance - Distance travelled by the car when the brakes are applied
and the car stops
Stopping distance - Sum of thinking distance and braking distance
Braking force - Frictional force applied by the road on the tyre in the opposite
direction to motion which causes the vehicle to come to rest
Work done - Force x distance moved in the direction of the force
