Question

In kinetics,when one block is placed on top of another is a pulley system,if one accelerate to the left,they get a negative acceleration while the one accelerating to the right gets positive acceleration.So negative sign not only means slowing down but also accelerate in opposite direction?

Answer 1

Slowing, that is, a decrease in the velocity modulus, occurs when the direction of the velocity and acceleration vectors is opposite; for example, positive acceleration can also cause deceleration if the projection of velocity is negative.

The answer to the question is this: negative acceleration can cause a slowdown, but it can also lead to an increase in speed, this is determined by the specific situation.