aqa as physics – mechanics exam questions and answers

aqa as physics – mechanics exam questions and
answers
Weight
Mass x Gravitational Field Strength


Vector
A quantity with size and direction


Scalor
A quantity with size only


Newton's 2nd Law
Resultant Force = mass x acceleration


Displacement
Position of an object relative to an origin


Average Speed
Distance Travelled / Time taken


Instantaneous Speed
distance travelled in an instant / time duration of an instant


Average Velocity
Change in displacement / time taken


Velocity
Gradient of displacement / time graph


Change in Displacement
Area under a velocity / time graph


Acceleration
Rate of change in velocity


Density
Mass / Volume


Fluid
Gas or Liquid


When the velocity reaches its greatest.
Terminal Velocity

, Viscous
a substance that is thick, sticky and resistive to flow


Moment
Force x Perpendicular Distance from axis to line of action


Principle of Moments
For an object in equilibrium, about any point, the sum of the clockwise moments = the sum of the
anti-clockwise moments


Centre of Gravity
The point at which the whole weight of the body appears to act


Newton
Force needed to accelerate a 1kg mass by 1m/s²


Torque
The same as a moment


Couple
A pair of equal but opposite forces seperated by a perpendicular distance


Change in Gravitational Potential Energy
mass x gravitational field strength x change in height


Kinetic Energy
½ x mass x velocity²


Work Done
Force x Distance moved in the direction of the force


Joule
The work done by a force of 1N in moving an object 1m in the direction of the force


Power (written)
The rate of doing work


Power (equation)
Work Done / Time Taken Or Energy Converted / Time Taken


Watt
The rate of working of 1J of work done in a second