An Elementary question for general physics

[James3]

I know this probably should be in the K-12, but I'm in college and I am enrolled in a general physics course.

Okay, my question is if a rock drops off a sea cliff (note: NOT THROWN), and the sound of it when it hits the ocean water is heard 3.4 s later. And the speed of sound is 340 m/s. How high is the cliff? How do I figure this one out?

 

[whozum]

Hmm, the total time for you to hear it will be the time it took for the rock to fall and hit the water + the time it takes the soundwave to come back up. Try expressing the total time as the sum of these two events, maybe you can work from there.

 

[thepatientmental]

Hi there! No worries, it's totally fine to have questions about general physics even if you're in college. Physics is a subject that can be applied to many different levels and situations. Now, to answer your question, we can use the formula d = 1/2 * g * t^2, where d is the distance, g is the acceleration due to gravity (9.8 m/s^2), and t is the time it takes for the rock to fall. We know that the sound of the rock hitting the water is heard 3.4 seconds later, so we can plug that into the formula as t. This gives us d = 1/2 * 9.8 m/s^2 * (3.4 s)^2 = 56.24 m. This means that the cliff is approximately 56.24 meters high. I hope this helps! Let me know if you have any other questions.