# Topic 2 – Motion and forces SPECIFICATION

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2.1 Explain that a scalar quantity has magnitude (size) but no specific direction

2.2 Explain that a vector quantity has both magnitude (size) and a specific direction

2.3 Explain the difference between vector and scalar quantities

2.4 Recall vector and scalar quantities, including:

a displacement/distance

b velocity/speed

c acceleration

d force e weight/mass

f momentum

g energy

2.5 Recall that velocity is speed in a stated direction

2.6 Recall and use the equations:

a (average) speed (metre per second, m/s) = distance (metre, m) ÷ time (s)

b distance travelled (metre, m) = average speed (metre per second, m/s) × time (s)

2.7 Analyse distance/time graphs including determination of speed from the gradient

2.8 Recall and use the equation:  acceleration (metre per second squared, m/s2) = change in velocity (metre per second, m/s) ÷ time taken (second, s)

( ) t uva − =

2.9 Use the equation:  (final velocity)2 ((metre/second)2, (m/s)2) – (initial velocity)2 ((metre/second)2, (m/s)2) = 2 × acceleration (metre per second squared, m/s2) × distance (metre, m)  x auv × ×=− 222

2.10 Analyse velocity/time graphs to:

a compare acceleration from gradients qualitatively

b calculate the acceleration from the gradient (for uniform acceleration only)

c determine the distance travelled using the area between the graph line and the time axis (for uniform acceleration only

2.11 Describe a range of laboratory methods for determining the speeds of objects such as the use of light gates

2.12 Recall some typical speeds encountered in everyday experience for wind and sound, and for walking, running, cycling and other transportation systems

2.13 Recall that the acceleration, g, in free fall is 10 m/s2 and be able to estimate…