Calculating the Distance a Rock Travels Up a Sloped Hill

[eglaud]

Homework Statement

A rock approaches the foot of a hill with a speed of 16 m/s. The hill has a slope of 23 degrees, how far up the hill does the rock travel?

Homework Equations

KE = PE

The Attempt at a Solution

I tried mv²/2 = mgy but I know this isn't right since I don't use theta at all. What do I do to change this?

 

[eglaud]

Is the equation KE = PE - W? This is what I did before, but I am unsure why except that I can plug in the angle, but I forgot to include this HILL IS FRICTIONLESS so I wouldn't have thought to use this.

 

[RedDelicious]

Homework Statement

A rock approaches the foot of a hill with a speed of 16 m/s. The hill has a slope of 23 degrees, how far up the hill does the rock travel?

Homework Equations

KE = PE

The Attempt at a Solution

I tried mv²/2 = mgy but I know this isn't right since I don't use theta at all. What do I do to change this?

Have you drawn a picture?

 

[eglaud]

Have you drawn a picture?

Yes, it looks like a rock moving towards a triangle

 

[haruspex]

how far up the hill does the rock travel?

mv²/2 = mgy

Presumably your y is the vertical ascent, but I don't think that is quite what the question is asking for.

 

[AgusCF]

Hello everybody. Sorry for my english. I am not native. I think you must calculate de kinetic Energy at the bottom of the hill. Then, you must calculate the position (dependent with the angle) at the velocity is 0 m/s.

 

[haruspex]

Hello everybody. Sorry for my english. I am not native. I think you must calculate de kinetic Energy at the bottom of the hill. Then, you must calculate the position (dependent with the angle) at the velocity is 0 m/s.

I think eglaud understands that but has not interpreted the question correctly. See my post #6.

 

[AgusCF]

I think eglaud understands that but has not interpreted the question correctly. See my post #6.

Ouch! Yeap you are right! And I think that the problem wants to calculate the distance that the rock goes up on the lateral of the hill.