Physics Notes
Kinematics
Displacement, Velocity, Acceleration
1. Frame of reference
a. This is a reference point from which other objects are observed.
2. One dimensional motion
a. This is when an object is contained back and forth along a line.
Position
1. Position is a measurement of location with reference to an origin.
2. Quantity symbol 𝑥
3. SI unit (m)
4. Position is a vector quantity that points from the reference point.
Distance
1. Distance is the length of path travelled.
2. Distance is a scalar.
3. SI unit (m)
Displacement
1. Displacement is the change in position of an object.
2. It is vector quantity that prints from the Xi to the Xf.
3. Quantity symbol: 𝛥𝑥
Differences between distance and displacement.
Distance Displacement
Depends on the path Independent of the path
Always positive Can be positive or negative
Is a scalar Is a vector
Speed
1. Speed is the distance (D) travelled divided by the time 𝛥𝑡 taken for the journey.
2. Quantity symbol – V (same as velocity)
𝐷
3. 𝑉 = 𝛥𝑡
4. SI unit – m/s or m.s-1
Velocity
1. Velocity is the rate of displacement.
𝛥𝑥
2. 𝑉 =
𝛥𝑦
3. SI unit m/s or m.s-1
1
,Average velocity
𝑣𝑖 +𝑣𝑓
1. 𝑉𝑎𝑟 = 2
Instantaneous velocity
1. Velocity at a particular point.
Acceleration
1. Acceleration is the rate of change of velocity.
𝛥𝑣
2. 𝑎 = 𝛥𝑡
Graphs of motion
1. Position time graph (acceleration = 0)
a. Gradient = velocity
b. Gradient/velocity is constant.
2. Position time graph (acceleration > 0)
a. Gradient/velocity is increasing.
b. Instantaneous velocity at any time is equal to the tangent of a point.
2
, 3. Position time graph (acceleration < 0)
a. Gradient/velocity is decreasing.
b. *
4. Velocity time graph (acceleration = 0)
a. Body remains at constant velocity.
b. Gradient/acceleration is 0.
5. Velocity time graph (acceleration > 0)
a. Velocity is increasing.
3
Kinematics
Displacement, Velocity, Acceleration
1. Frame of reference
a. This is a reference point from which other objects are observed.
2. One dimensional motion
a. This is when an object is contained back and forth along a line.
Position
1. Position is a measurement of location with reference to an origin.
2. Quantity symbol 𝑥
3. SI unit (m)
4. Position is a vector quantity that points from the reference point.
Distance
1. Distance is the length of path travelled.
2. Distance is a scalar.
3. SI unit (m)
Displacement
1. Displacement is the change in position of an object.
2. It is vector quantity that prints from the Xi to the Xf.
3. Quantity symbol: 𝛥𝑥
Differences between distance and displacement.
Distance Displacement
Depends on the path Independent of the path
Always positive Can be positive or negative
Is a scalar Is a vector
Speed
1. Speed is the distance (D) travelled divided by the time 𝛥𝑡 taken for the journey.
2. Quantity symbol – V (same as velocity)
𝐷
3. 𝑉 = 𝛥𝑡
4. SI unit – m/s or m.s-1
Velocity
1. Velocity is the rate of displacement.
𝛥𝑥
2. 𝑉 =
𝛥𝑦
3. SI unit m/s or m.s-1
1
,Average velocity
𝑣𝑖 +𝑣𝑓
1. 𝑉𝑎𝑟 = 2
Instantaneous velocity
1. Velocity at a particular point.
Acceleration
1. Acceleration is the rate of change of velocity.
𝛥𝑣
2. 𝑎 = 𝛥𝑡
Graphs of motion
1. Position time graph (acceleration = 0)
a. Gradient = velocity
b. Gradient/velocity is constant.
2. Position time graph (acceleration > 0)
a. Gradient/velocity is increasing.
b. Instantaneous velocity at any time is equal to the tangent of a point.
2
, 3. Position time graph (acceleration < 0)
a. Gradient/velocity is decreasing.
b. *
4. Velocity time graph (acceleration = 0)
a. Body remains at constant velocity.
b. Gradient/acceleration is 0.
5. Velocity time graph (acceleration > 0)
a. Velocity is increasing.
3
