A child throws a penny straight down into a wishing well. The penny's initial speed is 2 m/s. If the penny takes 3 seconds to hit the water, how deep is the well?
A. 20 m down
B. 46 m down
C. 50 m down
D. 94 m down

i cant figure this out :( i've gotten several different answers and i dont know how to find acceleration for this problem. i know this is a physics question but i posted it there and its been a long time and no one is helping me so i dont know what to do

Question

A child throws a penny straight down into a wishing well. The penny's initial speed is 2 m/s. If the penny takes 3 seconds to hit the water, how deep is the well?
	A.	20 m down
	B.	46 m down
	C.	50 m down
	D.	94 m down

i cant figure this out :( i've gotten several different answers and i dont know how to find acceleration for this problem. i know this is a physics question but i posted it there and its been a long time and no one is helping me so i dont know what to do

mathmale · Answer

In this problem you don't need "to find acceleration;" since the penny is in free fall, the acceleration is the acceleration due to gravity, or -9.8 meters/(second)^2 ('minus 9.8 meters per second squared').

anonymous · Answer

that definitely makes sense, thank you :D

mathmale · Answer

There are two equations that may be relevant and helpful here:
(1)  the velocity equation:  $$v(t)=at+v _{0}$$ and (2)the distance equation:
$$s(t)=s _{0}+v _{0}t+\frac{ 1 }{ 2 }at^2$$

mathmale · Answer

Have you seen / worked with these equations before?
What further help / info / guidance do you need to solve this problem?

anonymous · Answer

yes; i just finished filling out and solving the last equation you supplied and got -34.2 but i think that's incorrect.