How High is the Sea Cliff Based on Sound Travel Time?

[dwilson89]

Please help! I've been both conceptually blocked for quite some time and need help fast!
A rock is dropped from a sea cliff, and the sound of it striking the ocean is heard 4.0 later. Given the speed of sound is 340m/s, calculate how high the cliff is in meters.

 

[rl.bhat]

If h is the height of the cliff, time taken by the rock to fall is given by

h = 1/2*g*t1^2.

Time taken by the sound to reach the top of the cliff is t2 = h/340.

Now t1 + t2 = 4 s.

Substitute the values of t1 and t2 in the above equations and solve for h.

 

[dwilson89]

If h is the height of the cliff, time taken by the rock to fall is given by

h = 1/2*g*t1^2.

Time taken by the sound to reach the top of the cliff is t2 = h/340.

Now t1 + t2 = 4 s.

Substitute the values of t1 and t2 in the above equations and solve for h.

So do you mean solve to T1 in the first equation, then add the two together and solve for h?

 

[graphene]

Get t1 in terms of h. Then get t2 in terms of h.
& Substitute these into t1 + t2 = 4.