Summary Nova Physics 3TTO Chapter 4.1, 4.2 & 4.4

Summary Physics 4.1, 4.2 & 4.4


4.1 Accelerating and decelerating

Making a (V, T) diagram

- The (speed, time) diagram on the right is drawn according to the
data from the picture above.
o The is called a (v, t) diagram.
- From t=0s to t=4s, the motion is an accelerationthe speed is increasing
- By t=4s, the speed is constant  uniform motion
- The graph below is a (x, t) diagram (position agianst time)

Uniform acceleration

- A motion in which the speed increases at a steady rate is called a uniform
acceleration  the first 4 seconds on the graph
- Every second, the speed is increasing by 3 m/s. The change of speed per
second is called the acceleration
o This is written as 3 m/s2. And you say ‘’thee meters per second
squared’’ or ‘’three meters per second per second
o The symbol for acceleration is the letter a

Uniform deceleration

- When the speed decreases evenly the motion is a uniform deceleration
- The reduction speed each second is called the deceleration
- In the figure, the deceleration is -2m/s 2.  a=-2m/s2

Calculating the acceleration

Δv
a=
Δt
where:

- a is the acceleration is metres per second squared (m/s 2)
- Δv = vf – vi = the change in speed in metres per second (m/s)
- Δt = tf – ti = the change in time in seconds