y10 kinematics

speed

the rate of change of distance

formula for speed

delta distance/delta time 

is speed a scalar or vector quantity?

scalar

average speed

the average of instantaneous speeds over a period of time

formula for average speed

S_av = total distance/total time

instantaneous speed

how fast an object is moving at a certain moment

average vs instantaneous speed

instantaneous speed is how fast an object is moving at a single moment, while the average speed is the average of instantaneous speeds over a period of time

what does the gradient in a distance/time graph tell you?

the speed

what can you say about the gradient and the speed of this distance-time graph?

the gradient is 0 therefore the speed is 0

what can you say about the gradient and the speed of this distance-time graph?

the gradient is equal to distance/time and the speed is uniform

what can you say about the gradient and the speed of these distance-time graphs?

the gradient is equal to the instantaneous speed and the speed is non-uniform

what does the gradient tell you in a velocity/time graph?

the acceleration

what can you say about the acceleration and the gradient of this velocity-time graph?

the acceleration is uniform and the gradient is equal to velocity/time

what can you say about the acceleration and the gradient of this velocity-time graph?

the acceleration is 0 and the gradient is 0 therefore the speed is constant

what can you say about the acceleration and the gradient of these velocity-time graphs?

the acceleration is non-uniform and the gradient is equal to the instantaneous acceleration

scalar vs vector quantity

scalar quantity has magntitude and no direction, vector quantity has both a magnitude and a direction

distance

how far an object has travelled

formula for distance

d = s_avt

is distance a scalar or vector quantity?

scalar

displacement

a change in position of an object

how is displacement measured?

a straight line from the object’s starting to ending point

is displacement a scalar or vector quantity?

vector

velocity

the rate of change of displacement

formula for velocity

delta displacement/delta time

is velocity a scalar or vector quantity?

vector

negative velocity

when the body travels in the exact opposite direction

acceleration

the rate of change of velocity

formula for acceleration

delta velocity/delta time

is acceleration a scalar or vector quantity?

vector

what does negative acceleration mean if negative directions have not been defined?

positive acceleration = body is getting faster

negative acceleration = body is slowing down

what does negative acceleration mean if negative directions have been defined?

for something moving in the positive direction, negative acceleration = slowing down
for something moving in the negative direction, negative acceleration = speeding up

inertia

the natural tendency of an object to maintain its velocity

what does the law of inertia say?

• an object at rest tends to stay at rest

• a moving object tends to keep moving with the same speed in the same direction

• inertia is not a force

newton’s first law of motion

an object will keep moving with the same speed and direction unless acted on by a net force

newton’s third law of motion

every force has an equal and opposit reaction force

what must be the case between an action and a reaction force?

they must:

• be equal in size

• be opposite in direction

• be of the same type

• act on different objects

newton’s second law of motion

net force = mass x acceleration
newtons = kg x m/s²

what is the relationship between force and acceleration?

as force increases, mass increases

what is the relationship between mass and acceleration?

as mass increases, acceleration decreases

what is the relationship between force and mass?

as force increases, mass increases