mam, can u plz explain by giving eg, that how only that object speeds up which has either both +ve velocity and acceleration or both are -ve velocity and acceleration
example where both the velocity and acceleration are negative.
Assume the the positive direction is up
You can throw a stone straight up, when it eventually comes down its velocity points downward, thus is negative; and its acceleration, 9.8 m/s2, also negative. And we find the stone speeds up.
Examples of positive velocity and positive acceleration where the object speeds up is