Calculate Velocity & Time of Pencil Dropped from Elevator Moving at 5m/s

[lytien]

A pencil is dropped from inside an elevator moving 5m/s upward. Calulate the time it takes to drop from 1m to elevator floor and its velocity.


I approached as a velosy problem. Is this more of a Force problem ? I could calculate the velocity and time it took while the elevator was at a standstill, but got stuck when its in motion. Can someone please guide me in the right direction? THanks!

 

[lanedance]

maybe show some working so we can see where you went wrong

note the pencil will initially be moving up at 5m/s the same speed as the elevator & have a think about equivalence of inertial reference frames

 

[Phrak]

I could calculate the velocity and time it took while the elevator was at a standstill, but got stuck when its in motion. Can someone please guide me in the right direction? THanks!

The concept you should apply is Galilean relativity; the laws of physics are the same in all inertial frames.