Thread: Elevator

An elevator ascends from the ground with uniform speed. At time a boy drops a marble through the floor. The marble galls with uniform acceleration and hits the ground seconds later. Find the height of the elevator at time .

So we use the following equations:








So we probably have to consider 2 cases: the elevator and the marble.

Elevator









Am I on the right track?

Hello, tukeywilliams!

It's easier than you think . . .

An elevator ascends from the ground with uniform speed.
At time a boy drops a marble through the floor.
The marble falls with uniform acceleration m/s²
. . and hits the ground seconds later.
Find the height of the elevator at time .

The height of the marble is given by: .

. . where: .


The problem begins when the marble is dropped.

Hence: .
. . . . . .
. . . . . .

We have: .


We are told: .when

So we have: .

. . Therefore: .

Oh ok. Just had a mental block.

Thanks