(b) movement and position

distance-time graphs (1.3)

• distance on the y axis, time on the x axis

• gradient of the line (change in y / change in x) is the speed

• if the line is flat then the object is stationary

equation for average speed (1.4)

average speed = distance moved / time taken

S = D / T

investigate the motion of everyday objects such as toy cars or tennis balls (1.5)

• acquire a toy car, medium plank, crank and stopwatch

• measure the length of the plank

• crank the crank and set the plank on top

• choose a spot on the car that the person with the stopwatch will watch (easiest to use the end)

• start the stopwatch as the car is released from the top of the plank and stop the stopwatch once the spot has passed the end of the plank

• do the above 5 times and take the mean of the times

  • divide the distance by the mean of the 5 times and there’s the speed the toy car was going at!

equation for acceleration (1.6)

acceleration = change in velocity / time taken

a = (v - u) / t

velocity-time graphs (1.7, 1.8, 1.9)

• velocity on the y axis, time on the x axis

• gradient of the line (change in y / change in x) is the acceleration

• if the line is flat then the object is moving at a constant speed

• the area underneath the line is the distance travelled

equation for final speed² (1.10)

(final speed)² = (initial speed)² + (2 × acceleration × distance moved)

v² = u² + 2as