Term  Definition 
What is a Vector?  Must have MAGNITUDE and DIRECTION 
What is a Scalar?  Has only MAGNITUDE 
On a distance/time graph, what does the gradient tell you?  speed 
On a speed/time graph, what does the gradient tell you?  acceleration 
On a speed/time graph what does the area under the graph tell you?  Distance covered 
What is velocity?  Vector Distance in a given direction/time taken 
What is speed?  Scalar distance/time 
What is average speed?  Scalar total distance/total time 
What is average velocity?  Vector displacement/total time taken 
What are the 5 equations of motion?   v=u+at
 v^{2}=u^{2}+2as
 s=ut+at^{2}/2
 s=vtat^{2}/2
 s=(u+v)t/2

What is the condition for using the 5 equations of motion?  acceleration must be constant 
What is distance?  The total length that has been moved. 
What is displacement?  The direct distance between start and end points 
What does negative acceleration mean?  slowing down 
What is negative displacement?  displacement in the opposite direction 
What is acceleration due to gravity?  9.8 m/s^{2} ALWAYS acts downwards 
A particle is thrown vertically upwards. What is its velocity at its highest point?  zero 
What does equilibrium of forces mean?  horizontal forces add up to zero vertical forces add up to zero 
Is a force a vector or a scalar?  vector 
How do you find the magnitude of the resultant of 2 perpendicular forces?  Pythagoras 
How do you find the magnitude of the resultant of several non perpendicular forces  Find perpendicular components (ie i,j) of all forces and then use pythagoras. 
How do you find the angle at which a force is acting if you know its i and j components?  tan 
What is an i vector  a unit vector acting horizontally to the right 
What is a unit vector  a vector that has a magnitude (ie a length) equal to 1 
What is a j vector?  A unit vector acting vertically upwards 
How do you find the magnitude of a vector given in the form ai + bj?  
How do you find the direction of a vector given in the form ai + bj?  tanθ=b/a 
Give 3 facts about the vector A and the vector A   They have equal magnitudes
 They are parallel
 They point in opposite directions

Give 3 facts about the vectors A and B if A=B   They are equal in magnitudes
 They are parallel
 They point in the same direction

Give 3 facts about the vectors A and 2A   One is twice as long as the other
 They are parallel
 They point in the same direction

When using the formula F=ma, what does the F stand for  F is the resultant of all the forces acting upon a particle 
When 2 particles are connected, how do you find their acceleration?  F=ma for the whole system, taking the direction of movement as positive. 
When 2 particles are connected, how do you find the tension in the string joining them?  F=ma for one particle. If possible, use the particle which has +T acting upon it. 
How many diagrams must you draw when answering a question?  Draw a new diagram each time the information about the question changes. 
What is the formula for the maximimum friction (f_{max})?  f_{max}=μR 
In which direction does friction always act?  Friction always opposes motion, so it will always act in the opposite direction to the one the particle is moving in. 
If the pushing force is less than the maximum frictional force, what happens?  Nothing. The system is stationary, v=0 f=pushing force, so equilibrium is maintained 
If the pushing force is equal to the maximum frictional force, what happens?  Nothing. The system is at its limit. f_{max}=pushing force, so equilibrium is maintained. Although often v=0, it is possible for v to be present, but it will be constant. 
If the pushing force is greater than the maximum frictional force, what happens?  There is an imbalance of forces, so the particle accelerates 
When a body is said to be 'on the point of slipping', what does this mean  The system is at the limit f_{max}=pushing force v is constant (often = 0) 
What is a 'moment'?  The 'turning effect' which is dependent on the magnitude of the force and the distance the force is from the pivot. Moment = force x distance 
In a friction question, what does equilibrium mean?  The pushing force is less than or equal to f_{max} 
In a moments question, what does equilibrium mean?  All clockwise moments = all anticlockwise moments OR The sum of all the moments = 0 
What is momentum  The effect of a moving mass momentum = mass x velocity 
What is conservation of momentum  total momentum before = total momentum after Remember to draw before and after diagrams 
What are the units of momentum?  Ns 
What is impulse?  Impulse = change of momentum Impulse = mv  mu ALSO Momentum = Ft I = Ft = mv  mu 
What are the units of impulse?  Impulse is a change of momentum, so its units are the same as momentum, ie Ns 