Finding distance traveled up a ramp

AI Thread Summary
The discussion focuses on calculating the distance traveled up a ramp using various physics equations. The user attempts multiple methods to find the distance, including using force equations and velocity calculations, but initially arrives at incorrect values. Key points include the clarification that the components of weight must be accurately represented, particularly distinguishing between mg and its components mgx and mgy. The user ultimately resolves their confusion by correctly applying the average velocity formula to find the distance as 1310.90 meters. The conversation emphasizes the importance of using both x and y direction information for accurate calculations.
x2017
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Homework Statement


Untitled.png


Homework Equations


ΣFΔt=mΔv
ΣF=ma
v=d/t

The Attempt at a Solution


I already found the following for previous questions:
mg=-661.9
mgx=-3594.37
mgy=-649.91
Fx=2192.69
Fy=-1250.69
FF=-365.44
Vf=257.18
ΣFx=-1767.12

ATTEMPT #1
v=d/t
d=vt
d=(257.18)(10)
d=2571.80 (incorrect)

ATTEMPT #2
ΣFΔt=mΔv
ΣFΔt=m(d/t)
[ΣFΔt/m](t)=d
[(-1767.12)(10)/67.4]10=d
-2621.84=d

ATTEMPT #3
ΔV=Δd/Δt
ΔvΔt=Δd
(257.18-5)(10)=Δd
2521.80=Δd

I am not sure where I am going wrong!
 
Last edited:
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Your x and y components of the weight are greater than the weight.
 
TSny said:
Your x and y components of the weight are greater than the weight.
IMG_0105.JPG


I keep getting the same things (Sorry about the bad quality photo, but I figured this was best so the triangles I made can be seen).
 
In your pink triangle drawn on the inclined plane, note that mg is the hypotenuse. But in the work shown in the blue rectangle you have mgx as the hypotenuse.
 
TSny said:
In your pink triangle drawn on the inclined plane, note that mg is the hypotenuse. But in the work shown in the blue rectangle you have mgx as the hypotenuse.

If I use the pink triangle again for mgx and use cos I get mgx=121.63.
But I'm confused because I still got 3594.37 for mgy & that's much larger than mg (661.19) in the first place, so is that one incorrect?

EDIT: mgy has to be correct because I had to calculate the force of friction in a previous question with it and obtained the correct answer!
 
x2017 said:
But I'm confused because I still got 3594.37 for mgy & that's much larger than mg (661.19) in the first place, so is that one incorrect?

EDIT: mgy has to be correct because I had to calculate the force of friction in a previous question with it and obtained the correct answer!
In the pink box you got the correct value for mgy.

Your value for mgx now looks correct also.
 
TSny said:
In the pink box you got the correct value for mgy.

Your value for mgx now looks correct also.

Okay, thanks!

So am I supposed to use both when solving for distance or just the stuff in the x direction? I was only using the stuff in the x direction before.
 
You need to use the y direction information to help get the friction force. But once you have the friction, you just need to consider ΣFx = max.
 
TSny said:
You need to use the y direction information to help get the friction force. But once you have the friction, you just need to consider ΣFx = max.

Okay so:

ΣFx=max
Fx-FF-mgx=max
2192.69-365.44-121.63=67.4[(vf-vi)/Δt]
(1705.62/67.4)10=vf-vi
253.06=Δv

And this is where I get lost... I am stuck solving for a distance, I don't know how to proceed.
 
  • #10
Never mind, I figured it out!

d=[(vi+vf)/2]t
d=[(5+257.18)/2]10
d=1310.90m
 
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