physics question?

Question

Please answer this question and help me step by step to understand what to do. im having a hard time in my physics class i need some help, but once someone explains it to me, i can do the rest. please help.

A pair of glasses is dropped from the top of a 32.0m high stadium. A pen is dropped 2.00s later. How high above the ground is the pen when the glasses hit the ground? (Disregard air resistance. A= -g= -9.81 m/s^2)

Please help with anything you can. thanks :)

Answer 1

First, figure out how long it takes the glasses to hit the ground

I'm going to use g as 10 m/s^2, you can fix it later.

d=0.5gt^2
t^2=2d/g
t^2=2*32/10=6.4
t=2.53 secs

The Pen will therefore be .53 secs into its flight at the time the glasses hit the ground.

Height above the ground equals height of stadium less the distance droped in .53 seconds.

Distance droped = .5*at^2
D= .5*10m/sec^2*.53sec^2
= .5*10*(.53)^2
=5*(.28)
=1.4 m

H= 32-D
= 32-1.4
= 30.6

You can redo the problem using gravity at 9.81 m/sec^2

Answer 2

halfway