What is Speed

The distance travelled per second

What is speed measured in?

metres per second (ms^1)

How is distance calculated?

distance= speed x time

How is average speed calculated?

average speed= total distance travelled/total time taken
(vbar is the symbol for average speed)

What is instantaneous speed?

The speed at a particular instant in time.

Describe a method for measuring instantaneous speed,

A light gate, connected to a timer, should be positioned at X. The trolley, with a card of known length of card mounted on it, should be released and allowed to roll down the incline. When the card cuts the light beam the timer starts and when the light beam is restored the timer stops.

How is instantaneous speed calculated?

instantaneous speed= length of card/time for card to pass through light gate

Why is it better to measure the instantaneous speed using a light gate and timer rather than attempt it manually with a timer?

Delay in human reaction for manually

What's the difference between a scalar and a vector quantity?

a vector quantity requires a size and a direction, a scalar quantity only requires a size.

Name some scalar quantities.

Mass, time, energy, distance, speed.

Name some vector quantities.

Force, displacement, velocity, acceleration, weight.

What is the distance between distance and displacement?

Distance is the total amount travelled, displacement is the distance between the starting and finishing point.

How is velocity calculated?

velcoity= displaceent/ time taken

What is acceleration?

the change in speed per second.

What is acceleration measured in?

metres per second per second
(ms^2)

If the line on a speed vs time graph is horizontal what can be said about the speed?

it is constant.

How can distance travelled be calculated by a speedtime graph?

area under the line
(speed x time)

How is acceleration calculated?

Acceleration= change in speed/change in time
a=vu/t
v=u + at

What can a negative acceleration be described as?

deceleration

What can force change when applied to an object?

Direction, shape, motion(speed up, slow down , start, stop)

How is newton balance used to measure force?

When a force is applied to a spring it stretches the greater the applied force the greater the stretch of the spring.

What is a frictional force?

A force which opposes the motion of an object.

How can the size of a frictional force be decreased?

streamlining

What is Newton's First Law of Motion?

An object will remain at rest or continue to travel at constant speed in a straight line unless it is acted on by an unbalanced force.

What is mass?

a measure of the amount of matter present in an object.

What is weight?

the force of gravity acting on an object.

What is gravitational field strength?

the force of gravity acting on each kilogram of an object

How is weight calculated?

weight= mass x gravity

What is Newtons Second Law of Motion?

The acceleration of an object dis directly proportional to the unbalance force acting on the object and is inversely proportional to the mass of an object.

How is force calculated?

Force= Mass x Acceleration

What is gravity?

the force that pulls all objects towards the centre of the planet.

What is mass measured in?

kg

What is weight measured in?

Newtons (N)

What is gravitational field strength calculated in?

Nkg^1
