1.3.1 Speed of something and its
direction of travel
1.3.2 Velocity can be shown using an arrow ⟶
1.3.3 Velocity is a quantatie that may have
direction as well as magnitude and so
it is called a vector
2 Accelaration
2.1 average acceleration=change in velocity/time taken
2.2 Unit
m/s²
2.3 negative acceleration is called deceleration
2.4 Uniform acceleration means constant acceleration
3 Motion Graphs
3.1 Distance-time graphs
3.1.1 Gradient of the line is numerically equal to the speed
3.1.1.1 Gradient = y/x
3.1.2 Different objects can show if the object
is at a steady speed or stationary
3.1.3 The graph can also show that the object
is accelerating or deccelerating
3.2 Speed-time graphs
3.2.1 Gradient of the line is
equal to the acceleration
3.2.2 Area under the line is equal to
the distance travelled
3.3 Uniform and non-uniform acceleration
3.3.1 Uniform
3.3.2 Non-uniform
4 Free fall
4.1 Unit
g
4.1.1 On earth
10m/s²
4.1.2 g decreases as the object is
moved away from each
4.2 Acceleration of free fall- Same for all objects falling
near the earth's surface, either light or heavy
4.3 When throwing a ball at the air...
4.3.1 Upward velocity of 30m/s is equal to downward
velocity of -30m/s
4.3.2 Whatever the ball is travelling up or down it is
gaining downward velocity at the rate of 10m/s
(g)
5 Forces in balance
5.1 Force
5.1.1 Unit
Newton(N)
5.1.2 Small forces can be measured using a spring
balance. The greater the force the more the
spring is stretched and higher it is the reading
on the scale
5.1.3 Examples of different forces
5.1.3.1 Tension
5.1.3.2 Upthrust
5.1.3.3 Weight
5.1.3.4 Friction
5.1.3.5 Air resistance
5.1.4 If many forces in an object are in balance,
they cancel each other out
5.1.4.1 With balanced forces on it, an object is
either at rest, or moving at a steady
velocity
5.1.5 Terminal velocity
5.1.5.1 Example: a skydiver falling
from a hovering helicopter
5.1.5.1.1 As her speed increases, the air resistance on her also
increases. Eventually, it is enough to balance her weight, and
she gains no more speed. She is than at her terminal velocity.
5.2 Newton's first law of motion (if no external force is
acting on it the object will)
5.2.1 if stationary, remain stationary
5.2.2 if moving, keep moving at a steady speed in a straight line
6 Force, mass and acceleration
6.1 Inertia
6.1.1 Resistance to a change in velocity or
direction
6.1.2 The more mass something has, the more inertia it has
6.2 Resultant force
6.2.1 When two forces are unbalanced. Together, they are
equivalent to a single force. This is called the resultant force
6.2.2 Resultant force is equal to zero when forces are balanced,
and there is no acceleration
6.3 Resultant force= mass x acceleration
6.3.1 F=ma
6.3.2 Newton's second law of motion
7 Force, weight and gravity
7.1 Gravitattional force
7.1.1 All masses attract each other
7.1.2 The greater the masses, the
stronger the force
7.1.3 The closer the masses, the
stronger the force
7.1.4 Gravitational field strength (g)
7.1.4.1 Region in which a mass experiences a
force due to gravitational attraction
7.1.4.2 weight= mass x g
7.1.4.2.1 w=mg
7.2 Weight
7.2.1 Measured in newtons
7.2.2 Near the earth's surface, an object of
mass 1 kg has a weight of 9.8 N
7.2.3 Weight can change from place to place, but mass
remains the same