Calculating Time Interval of Splash from Two Stones Dropped

[Pakbabydoll]

A mountain climber stands at the top of a 59.4 m cliff that over hangs a pool of water. He throws 2 stones vertically downwards 1.77s apart and they cause a single splash.
first stone initial velocity= -2.06m/s
acceleration of gravity 9.8m/s^2
How long after release of first stone will the two hit water? in units of s.



2. what's the formula to do this problem. I am completely lost!

 

[LowlyPion]

A mountain climber stands at the top of a 59.4 m cliff that over hangs a pool of water. He throws 2 stones vertically downwards 1.77s apart and they cause a single splash.
first stone initial velocity= -2.06m/s
acceleration of gravity 9.8m/s^2
How long after release of first stone will the two hit water? in units of s.

2. what's the formula to do this problem. I am completely lost!

Which of the kinematic formulas below do you think would be useful getting you the answer?
https://www.physicsforums.com/showpost.php?p=905663&postcount=2

 

[Pakbabydoll]

initially I started using
x = x_0 + v_0 t + (1/2) a t^2
and
v = v_0 + a t
but I always end up with two unknowns (A and T)
so now I am completely lost.

 

[LowlyPion]

initially I started using
x = x_0 + v_0 t + (1/2) a t^2
and
v = v_0 + a t
but I always end up with two unknowns (A and T)
so now I am completely lost.

Start solving for what you can then?

You know the height of the cliff.
You know initial velocity.

Just curious why you think "a" is unknown when they give it to you as 9.8 m/s².

 

[Pakbabydoll]

I got it thanks :) I was just having a panic moment with that problem.

 

[LowlyPion]

I got it thanks :) I was just having a panic moment with that problem.

Just remember to take a breath then next time and start working from what you know and develop what you can. Then who knows but you may arrive at the answer?

Good luck.