My Math Forum  

Go Back   My Math Forum > Science Forums > Physics

Physics Physics Forum


Thanks Tree1Thanks
Reply
 
LinkBack Thread Tools Display Modes
January 8th, 2017, 11:20 AM   #1
Member
 
Joined: Jan 2017
From: Huddersfield

Posts: 30
Thanks: 0

physics

hi everyone, i am currently doing a degree in mechanical engineering and i am currently struggling with an assignment.

Basically we did an experiment where a roller disc was rolled down 2 rails and we had to calculate how long it takes to get from one end to the other, it was raised at 10cm increments each time and obviously the higher the gradient the quicker it got to the bottom.

we then have to calculate things such as radius of gyration, kinetic energy, potential energy and kinetic energy of rotation. now in one of the tables there is values given as S (m) - this is the distance of the rails
t (s) - Time in seconds
v (m/s) - velocity
v^2 (m/s^2) - ?
h (m) - height

i am also given a statement that says
the final linear velocity v is found from s = 1/2(u+v)t
now i have transposed this to 2s/t - u = v but how do i find v^2?
Jimkeller1993 is offline  
 
January 8th, 2017, 11:44 AM   #2
Math Team
 
Joined: Jul 2011
From: Texas

Posts: 2,675
Thanks: 1337

$v^2 = \left(\dfrac{2s}{t}-u\right)^2$

should be rather simple, espescially if initial velocity, $u=0$
skeeter is offline  
January 8th, 2017, 11:54 AM   #3
Member
 
Joined: Jan 2017
From: Huddersfield

Posts: 30
Thanks: 0

so thats all i have to do? maybe i looked a bit too in depth into it.
also once plotting a graph with with height on the vertical axis and v^2 on the horizontal how would i find the value of (h/v^2)?
Jimkeller1993 is offline  
January 8th, 2017, 12:04 PM   #4
Math Team
 
Joined: Jul 2011
From: Texas

Posts: 2,675
Thanks: 1337

$\dfrac{h}{v^2}$ would be the slope of the graph ...
skeeter is offline  
January 8th, 2017, 12:08 PM   #5
Member
 
Joined: Jan 2017
From: Huddersfield

Posts: 30
Thanks: 0

and how do i find that?
this is the first physics topic we have done and its certainly not my strongest subject
Jimkeller1993 is offline  
January 8th, 2017, 12:12 PM   #6
Math Team
 
Joined: Jul 2011
From: Texas

Posts: 2,675
Thanks: 1337

I would start by plotting a data graph of $h$ vs $v^2$ ...
Thanks from Joppy
skeeter is offline  
January 8th, 2017, 12:17 PM   #7
Member
 
Joined: Jan 2017
From: Huddersfield

Posts: 30
Thanks: 0

yes i have plotted the graph, i just dont know how to find the gradient
Jimkeller1993 is offline  
January 8th, 2017, 12:51 PM   #8
Math Team
 
Joined: Jul 2011
From: Texas

Posts: 2,675
Thanks: 1337

Have you constructed a line of best fit to your data? The data should follow a linear pattern.
skeeter is offline  
January 8th, 2017, 12:56 PM   #9
Member
 
Joined: Jan 2017
From: Huddersfield

Posts: 30
Thanks: 0

yes the line of best fit is a linear pattern
Jimkeller1993 is offline  
January 8th, 2017, 01:00 PM   #10
Math Team
 
Joined: Jul 2011
From: Texas

Posts: 2,675
Thanks: 1337

Quote:
Originally Posted by Jimkeller1993 View Post
yes the line of best fit is a linear pattern
Then measure the slope ... $\dfrac{rise}{run}$, remember?
skeeter is offline  
Reply

  My Math Forum > Science Forums > Physics

Tags
physics



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Physics IB alex77 Physics 2 August 15th, 2016 02:27 AM
Discrepancies in particles physics versus quantum physics GreenBeast Physics 16 April 8th, 2016 07:16 AM
physics maapony Algebra 1 September 1st, 2011 03:34 PM
physics help shawdub Physics 1 October 29th, 2010 06:11 PM
Physics johnny Physics 11 October 30th, 2007 06:19 AM





Copyright © 2017 My Math Forum. All rights reserved.