what is the definition of displacement?
the distance the object has moved from its starting position (vector quantity of distance)
what is the definition of instantaneous speed?
the speed at a specific point in time of a journey
what is the definition of average speed?
the total distance / total time taken
what is the gradient on a displacement-time graph?
the object’s velocity
what does a straight line (constant gradient) on a displacement-time graph show?
a constant velocity
what is the gradient on a displacement-time graph?
the object’s velocity
what does a curve indicate on a displacement-time graph show?
velocity is not uniform
what does a curve of increasing positive gradient indicate on a displacement-time graph show?
object is accelerating (speeding up)
what does a curve indicate on a displacement-time graph show?
velocity is not uniform
what is the gradient on a velocity-time graph?
the object’s acceleration
what is the area under the curve on a velocity-time graph?
the object’s total displacement
what does a straight line (constant +ve gradient) indicate on a velocity-time graph show?
constant positive acceleration
what does a straight line (constant -ve gradient) indicate on a velocity-time graph show?
constant negative acceleration
what does a flat horizontal line indicate on a velocity-time graph?
constant velocity (not changing velocity)
what does a curve indicate on a velocity-time graph?
tells us that the velocity change is not uniform (the acceleration isn’t uniform)
what are the five suvat equations?
v = u + at v^2 = u^2 + 2as s = ut + 0.5at^2 s = vt - 0.5at^2 s = 0.5(u + v)t
when can you use and apply suvat equations?
for an object moving with CONSTANT ACCELERATION
outline an investigation to see how collisions affect the motion of a trolley
- set up an experiment with a ramp and a trolley at the top with a wall at the bottom of the ramp and a metre ruler in between ramp and wall and a video camera side on to record it
- measure the length of the trolley, L, turn on the video camera and start recording
- place trolley on start line and once the trolley has hit the wall stop recording
-to investigate the final velocities of two trolley coliding, position two trolleys on a smooth surface with a metre
ruler parallel
-measure the lengths of the two trolleys, L, and turn on video camera and record, push one trolley so hits other and stop recording
To calculate velocity:
using video analysis software, you can view frame by frame, pick a point of reference on the metre ruler and count how many frames it takes a trolley to pass that point, knowing the frame rate (no. of frames per second), the time, t, taken for the trolley to pass the point = no.of frames for trolley to pass point x 1 second/frame rate
-use L for length of trolley to do v = L/t
outline an investigation to see how collisions with a wall and another trolley affect the motion of a trolley
- set up an experiment with a ramp and a trolley at the top with a wall at the bottom of the ramp and a metre ruler in between ramp and wall and a video camera side on to record it
- measure the length of the trolley, L, turn on the video camera and start recording
- place trolley on start line and once the trolley has hit the wall stop recording
-to investigate the final velocities of two trolley coliding, position two trolleys on a smooth surface with a metre
ruler parallel
-measure the lengths of the two trolleys, L, and turn on video camera and record, push one trolley so hits other and stop recording
To calculate velocity:
using video analysis software, you can view frame by frame, pick a point of reference on the metre ruler and count how many frames it takes a trolley to pass that point, knowing the frame rate (no. of frames per second), the time, t, taken for the trolley to pass the point = no.of frames for trolley to pass point x 1 second/frame rate
-use L for length of trolley to do v = L/t
what is freefall?
- freefall is the acceleration of a body under the action of a gravitational field, with air resistance and buoyancy being ignored
- objects of different masses fall at the same rate under the influence of gravity
- freefall occurs when the only force acting on the object is its weight
outline an investigation that looks at what affects the motion of a trolley on a slope
- to see how the distance a trolley has rolled effects it’s velocity
- set up an experiment with a trolley at the top of a ramp with a light gate at the bottom which is also connected to a data logger
- measure the length of the trolley, the angle of the ramp (theta) and the distance from the chosen start line to light gate, d (mark start line on ramp)
- place the trolley on the line and let go (meaning u = 0), the data logger will record the time taken for the trolley to pass through the light gate and calculate the velocity at this point
- change the starting position to vary d
- repeat to gain average velocities and to reduce error and record results
- use s = 0.5(u + v)t
what is the relationship between acceleration, force and mass?
acceleration is directly proportional to the force acting on it but inversely proportional to its mass (f = ma)
outline an investigation to determine g using a trapdoor and an electromagnet
- set up a circuit with an electromagnet supporting a steel ball, a switch, a timer and a trapdoor directly underneath the ball bearing
- when the current is switched off, the ball begins to fall and and the timer simultaneously starts
- once it hits the trapdoor the timer is stopped
- the distance, s, between the bottom of the ball bearing and the trapdoor is measured using a ruler and the time, t, is taken from timer readings
- repeat to get an average for t
- u = 0 because the ball starts from rest therefore can use suvat —> s = 0.5at^2, rearrange and solve for g
- alternatively a graph can be plotted of s (y axis) against t^2 (x axis) so the gradient = 0.5g (as y intercept is 0)
(note if the distance is too large air resistance might have a noticeable effect on the speed, also the height can causes uncertainty, ensure accurate measurement)
outline an investigation to determine g using lightgates
- use lightgates and a data logger to measure the time e taken fro a piece of card to travel through the light gate as it falls
- blu-tack can be added to the corners of the card to stabilise it better
- the data logger can record the velocity or you can use a timer and work out the average velocity of card is given by L/t where L is the length of the card and t is the transit time recorded by the timer for the card to travel through the light gate
- use a ruler to measure the vertical height of the card above the light gate, s
- hold the card vertically above the lightgate before releasing it
- use suvat, u = 0 because initially from rest so use —> v^2 = 2as, rearrange and solve for g
- varying the height allows a graph to be plotted, v^2 on y axis and s on x axis, gradient = 2g
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2.1 Physical Quanities & Units11
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2.2 Making Measurements & Analysing Data18
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2.3 Nature of Quantities8
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3.1 Motion34
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3.2 Forces in Action46
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3.3 Work, Energy & Power30
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3.4 Materials43
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3.5 Newton's Laws of Motion & Momentum23
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4.1 Charge & Current21
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4.2 Energy, Power & Resistance48
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4.3 Electrical Circuits25
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4.4 Waves82
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4.5 Quantum Physics31
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5.1 Thermal Physics67
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5.2 Circular Motion25
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5.3 Oscillations41
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5.4 Gravitational Fields26
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5.5 Astrophysics & Cosmology90
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6.1 Capacitors24
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6.2 Electic Fields26
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6.3 Electromagnetism58
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6.4 Nuclear & Particle Physics116
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6.5 Medical Imaging51
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Deriving Equations (ALL)6
