Physics P2a revision

difference between velocity and speed

velocity is vector quantity
speed is scalar quantity

what do scalar quantities have

only a magnitude (size)

what do vector quantities have

has a magnitude (size) and a direction

equation for average speed

distance / time

how far would a runner travel in 30 seconds if she travels at a constant speed for 3m/s

90m

a cyclist travels at a constant speed of 5m/s for 1minute, before speeding utp instantly o 10m/s for 10 seconds. how far does the cyclist travel overall?

400m

If a car travelling at a velocity of 10m/s suddenly turns around and continues at the same speed, what is is new velocity ?

-10m/s

what does the length of an arrow represent

the magnitude (size) of a quantity

what does the direction of the arrow represent

the direction of the vector quantiity

what is the difference between a scalar and a vector

a vector has direction and magnitude

3 examples of vector quantities

velocity
force
acceleration

equation for acceleration

change in velocity/ time taken

what is acceleration measured in

metres per second squared

a ball rolling down a hill accelerates uniformly from rest to a velocity of 5m/s in 10 seconds. what is the acceleration of the ball

0.5m/s^2

3 examples of scalar quantities

- temperature
- mass
-energy

what is displacement

the distance an object moves in a straight line from starting point to a finishing point

is displacement vector or scalar quantity

vector quantity

what is distance

how far an object moves

is distance scalar or vector quantity

scalar quantity

when do non contact forces happen

when objects are separated and not touching

examples of non contact forces

gravitational force
electrostatic force
magnetic force

when do contact forces happen

when two objects are physically touching

examples of contact forces

friction
air resistance
tension

if an object travels 4 metres down then 2 metres backwards, what is the distance travelled? what is the objects displacement?

total distance= 6 metres
displacement = 2 metres

what is an interaction pair

set of 2 forces that are equal and opposite, acting on 2 interacting objects

on a line graph how is a constant speed shown

by a straight line

on a line graph how is a stationary object shown

if the line is horizontal

area of a triange

0.5 x base x height

area of a rectangle

base x height

if an object travels 15 metres in 5 seconds, what is the slope of its distance-time graph

3m/s

if an object travels at 10 m/s constantly for 1 minute, how far will it have travelled

600m

a sprinter ran 100m in 9.71 seconds. what was his average speed? 2dp/rounded

10.3

how far would a runner travel in 33 seconds if she travels at a constant speed of 6m/s

198m

how far would a runner travel in 31 seconds if she travels at a constant speed of 4m/s

124m

a ball rolling down a hill accelerates uniformly from rest to a velocity of 26m/s in 14 seconds. what is the acceleration of the ball? 2dp/rounded

1.86 m/s^2

a ball rolling down a hill accelerates uniformly from rest to a velocity of 9m/s in 9 seconds. what is the acceleration of the ball? 2dp/rounded

1m/s^2

if an object is travelling at a velocity of 6ms^-1, then decelerates for 2 seconds at which point its velocity is 2ms^-1 , what is the acceleration of the object?

a ball is initially at rest and travels 9m. the ball travels at an acceleration of 10.7m/s^2. what is the final velocity of the ball? 1dp

1.2 m/s

a car starts at rest and accelerates at a constant rate of 30mph in 10 seconds. what does its velocity-time graph look like?

straight line with a positive gradient

which property of a velocity time graph gives the distance travelled by the car

area

equation for speed

distance/time(taken)

what is mass

measure of amount of matter an object contains

what is inertia

the measure if how difficult it is to change an objects motion

equation for weight

weight = mass x gravitational field strength

what is an objects centre of mass

a single point where all the mass appears to be

when will an object topple

when its centre of mass is located outside its base

what is the resultant force

sum of all forces acting on an object

equation for the resultant force

resultant force= mass x acceleration

if forces act along the same line, the resultant force can be calculated using what equation

forces acting in one direction - forces acting in opposite direction

2 types of deformation

elastic
inelastic

equation for hookes law

spring constant x spring extension

what is the springs constant

how stiff the spring is

how to work out the extension of spring

length of spring with masses - original length of spring

equation for spring extension

force applied / spring constant