Question

(i) When do you say that an object has positive acceleration? (ii) When do you say that an object has negative acceleration?

Answer 1

(i) When do you say that an object has positive acceleration?
Ans. When the initial velocity (u) is smaller than the final velocity (v) , which means the body has increase in velocity...we say the body is in positive acceleration..
(ii) When do you say that an object has negative acceleration?
Ans. When the initial velocity (u) is greater than the the final velocity (v).. which means that any force is applied in opposite direction, which leds to negative acceleration, (retardation).....

Answer 2

Answer:

1) When an object is speeding up, the acceleration is in the same direction as the velocity. Thus, this object has a positive acceleration.

2)the object is slowing down then its acceleration vector is directed in the opposite direction as its motion (in this case, a negative acceleration).

hope it will help you