Question

A lift is ascending with decreasing speed. What are the directions of velocity and acceleration of the lift at the given instant.

Answer 1

Answer:

Explanation: The question says that lift is ascending upwards. Hence it's velocity is directed vertically upwards. While as it has been mentioned that it's speed is decreasing then it implies that it's acceleration must be opposite to that of velocity. Hence it's acceleration is directed vertically downwards

Answer 2

A lift is ascending with decreasing speed is explained by the following case:

• As the lift is ascending then at that point of time the lift is moving upward with decreasing speed.
• At that point the acceleration is opposite to the direction of motion.
• Then the resultant be seen as R=mg+ma
• Here in this case the apparent weight of body is greater than actual weight.
• There are more case when the lift is moving downward then the apparent weight is less than the actual weight.