Chapter 7: Motion

Uniform Acceleration: When an object is travelling in a straight line with an increase in velocity at equal intervals of time, then the object is said to be in uniform acceleration.

The free-falling of an object is an example of uniform acceleration.

Non-Uniform Acceleration: When an object is travelling with an increase in velocity but not at equal intervals of time is known as non-uniform acceleration.

Bus moving or leaving from the bus stop is an example of non-uniform acceleration.

Given, the initial velocity (u) = 80km/hour = 80000m/3600s= 22.22 m.s^-1

The final velocity (v) = 60km/hour = 60000m/3600s= 16.66 m.s^-1

Time frame, t = 5 seconds.

Therefore, acceleration (a) =(v-u)/t = (16.66 m.s^-1 – 22.22 m.s^-1)/5s

= -1.112 m.s^-2

Therefore, the total acceleration of the bus is -1.112m.s^-2. It can be noted that the negative sign indicates that the velocity of the bus is decreasing.

Given parameters

Initial velocity (u) = 0

Final velocity (v) = 40 km/h

v = 40 × (5/18)

v = 11.1111 m/s

Time (t) = 10 minute

t = 60 x 10

t = 600 s

Acceleration (a) =?

Consider the formula

v = u + at

11.11 = 0 + a × 600

11,11 = 600 a

a = 11.11/600

a = 0.0185 ms^-2