Low Level Physics Problem 1D Motion

In summary, the rock was dropped from a height of 56.7 meters and the sound of it striking the ocean was heard 3.4 seconds later.
  • #1
Maskkkk
7
0
47.

A rock is dropped from a sea cliff and the sound of it striking the ocean is heard 3.4s later. If the speed of sound is 340 m/s, how high is the cliff?

Could somebody map this one out for me, it isn't making any sense.
 
Physics news on Phys.org
  • #2
Solve the equations.
 

Attachments

  • Picture.GIF
    Picture.GIF
    2.1 KB · Views: 480
  • #3
First, do you know a formula for distance an object falls in t seconds?
Solve that for t1 (the time until the rock hits the water) as a function of d (the height of the cliff).

Second, you are given that the speed of sound is 340 m/s so you can calculate the time, t2 necessary for the sound to come back up a distance d.

Since t1+ t2= 3.4 seconds, you can add those two formulas, involving d, to get an equation. Solve the equation for d.
 
  • #4
Umm...Another question. Where in the world are you standing to hear the splash?
 
  • #5
Since the acceleration of the rock is uniform i.e under the affect of gravity, couldn't you use the equations of motion?

u=0, a = 9.81, t = 3.4

s=ut+0.5xat^2
s=0.5*9.81*3.4^2
s=56.7m

I know that's not the information he was given but would it work? The only assumption I've made is that the rock was dropped from rest.
 
  • #6
The time given in this question is not the time the rock takes to reach the ocean but is the total time the rock reaches the ocean plus the time for the splash sound to travel back to the dropper. So i don't think it would work here.
 
  • #7
Leong said:
The time given in this question is not the time the rock takes to reach the ocean but is the total time the rock reaches the ocean plus the time for the splash sound to travel back to the dropper. So i don't think it would work here.

Ah yes, you are right. I didn't think :blushing: :smile:
 

What is 1D motion in physics?

1D motion in physics refers to the movement of an object in one direction, typically along a straight line. It is a simplified version of motion in which only one coordinate, usually distance or displacement, is considered.

What is a low level physics problem?

A low level physics problem is a basic or introductory problem that involves applying fundamental concepts of physics, such as Newton's laws of motion, to solve a given scenario or situation.

How do you solve a 1D motion problem?

To solve a 1D motion problem, you need to identify the given information, such as initial and final position, velocity, and time. Then, you can use the equations of motion, such as d = vt, to calculate the missing variables and solve for the unknown.

What are some common misconceptions about 1D motion?

One common misconception about 1D motion is that an object's speed and velocity are always the same. However, speed is a scalar quantity that only measures the magnitude of an object's motion, while velocity is a vector quantity that also includes direction.

Another misconception is that an object at rest has no acceleration. In reality, an object at rest still experiences acceleration due to gravity, which is equal to 9.8 m/s^2 on Earth.

What real-world applications use 1D motion?

1D motion is used in various real-world applications, such as calculating the distance traveled by a car or the time taken for a train to reach its destination. It is also commonly used in sports, such as track and field events, to measure an athlete's performance in terms of speed and distance.

Similar threads

  • Introductory Physics Homework Help
Replies
9
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
724
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
8
Views
2K
  • Introductory Physics Homework Help
Replies
10
Views
2K
  • Introductory Physics Homework Help
Replies
10
Views
4K
  • Introductory Physics Homework Help
Replies
6
Views
4K
  • Introductory Physics Homework Help
Replies
15
Views
4K
  • Introductory Physics Homework Help
Replies
8
Views
6K
Back
Top