Acceleration - Acceleration is seen in non-uniform motion and it can be defined as the rate of change of velocity with time.

• Acceleration (a) = Change in velocity/Time = (v-u)/t

where, v = final velocity, u = initial velocity

•  If v > u, then ‘a’ will be positive (+ve).

Retardation/Deceleration - Deceleration is seen in non-uniform motion during decrease in velocity with time. It has same definition as acceleration

• Deceleration (a') = Change in velocity/Time = (v-u)/t
• Here, v < u, ‘a’ = negative (-ve).
• It is a vector quantity.
• SI unit – m/s2 ( meter per second square)

Example 1: A car speed increases from 40 km/hr to 60 km/hr in 5 sec. Calculate the acceleration of car.

Example 2: A car travelling with a speed of 20 km/hr comes into rest in 0.5 hrs. What will be the valu of its retardation?

EXAMPLE 3 : If the velocity of the car reduced to 80 m/s from 120 m/s in 8 seconds on applying breaks . Calculate its acceleration.

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## Batch List #### Class IX SCIENCE BATCH

Course : CBSE Class 9

Start Date : 15.08.2022

End Date : 31.12.2022

Types of Batch : Classroom

 Subject M T W T F S S Science(6 hours) 2:45 PM 2:45 PM 2:45 PM 2:45 PM 2:45 PM 2:45 PM 3:45 PM 