Question

Please Help!

A stone falls on a ledge and takes 8 seconds to hit the ground. The stone has an original velocity of 0 m/s. How tall is the ledge?

A. 39.2 meters
B. 78.4 meters
C. 1254.4 meters
D 13.58 meters

Answer 1

http://www.physicsclassroom.com/Class/1DKin/U1L6a1.gif
Top right equation

Answer 2

s= ut + (at^2)/2

u=0
t= 8
a=9.8

work out s for th eheight

Answer 3

have you written this correctly? - none of th eanswers seem correct to me

Answer 4

yes i did

Answer 5

@agent0smith
it is not tgh etop right equation - they do not want the final velocity - they weant th edistance
top left equation.

But none of the given answers fits the question

Answer 6

Top left.

Answer 7

You knew what i meant!

Answer 8

I knew - but th eposter didn't

Answer 9

Well, I knew what I meant.

Answer 10

Okay so then I don't use the equation @MrNood posted

Answer 11

I didn't even notice, lol

And no answers are correct

Answer 12

The building should be approx. 320 m high.

Answer 13

Okay so I just realized I did put down the wrong thing

Answer 14

using
d= ut + 0.5 a t^2

u=0
a=9.81
t=8

d=0 + 9.81 *64/2 =314 m

none of the answers are correct - check again thast you wrote the question correctlyy

Answer 15

D. is actually 313.6 m

Answer 16

*lowers head in shame* Sorry

Answer 17

forgiven :-)

Answer 18

BTW - Empire State Building is 380m

Answer 19

lol thanks