Question

explain acceleration in positive and negative and zero with an example

Answer 1

Positive:- When velocity increases in the opposite direction of motion. Eg- a car starting from rest acquires a velocity of 2m/s in 2s while moving in straight line, a freely falling body.

Negative:- When velocity of body decreases in direction of motion. Eg- when we apply brakes of a car, an object thrown up.

Zero:- When the object is moving with constant or uniform velocity with time. Eg- a car is travelling at velocity of 2m/s for first 2 secs and maintains it for the next 2 secs

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Answer 2

when the velocity of a body increases with a time , its acceleration is positive
example a body dropped from a certain height gain velocity as it falls down towards the earth.
when the velocity of a body decreases with a time , its acceleration is negative it is also called retardation example when a ball is thrown vertically upwards its velocity decrease
Acceleration is change in velocity of an object per unit time ,so if the velocity remains constant for a particular period then the change in velocity in per unit time is zero. Therefore acceleration is zero Hence constant velocity is an example of zero acceleration .
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