October 29th, 2016, 02:23 AM  #1 
Member Joined: May 2016 From: Ireland Posts: 84 Thanks: 1  system of particles
Two particles of masses 3 kg and 5 kg are connected by a light inextensible string, of length 4 m, passing over a light smooth peg of negligible radius. The 5 kg mass rests on a smooth horizontal table. The peg is 2.5 m directly above the 5 kg mass. The 3 kg mass is held next to the peg and is allowed to fall vertically a distance 1.5 m before the string becomes taut. does any one know what this question looks like i cant even imagine it

October 29th, 2016, 07:18 AM  #2  
Math Team Joined: Jul 2011 From: Texas Posts: 2,311 Thanks: 1135  Quote:
 
October 30th, 2016, 12:51 AM  #3 
Member Joined: May 2016 From: Ireland Posts: 84 Thanks: 1 
Show that when the string becomes taut the speed of each particle is 3root3g all over 8 m/s i tried working this out by looking at the 3kg weight and using the equation v=u+2as u=0 a=g s=1.5 however working this out gives me an answer of root3g this is not the desired answer 
October 30th, 2016, 06:25 AM  #4  
Math Team Joined: Jul 2011 From: Texas Posts: 2,311 Thanks: 1135  Quote:
final velocity of the 5 kg mass = $v_f$ initial velocity of the 5 kg mass = $0$ final velocity of the 3 kg mass = $v_f$ because its motion is opposite in direction to the 5 kg mass initial velocity of the 3 kg mass = $\sqrt{3g}$ $Mv_f = m(v_f  v_0)$ solving for $v_f$ ... $v_f = \dfrac{mv_0}{M+m} = \dfrac{3\sqrt{3g}}{8}$  

Tags 
particles, system 
Search tags for this page 
Click on a term to search for related topics.

Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Discrepancies in particles physics versus quantum physics  GreenBeast  Physics  16  April 8th, 2016 06:16 AM 
To find a system of coordinates for visualise a system of equations  Jhenrique  Geometry  1  August 29th, 2015 06:33 AM 
Helium Deuterium capacitor of the distance nucleus affects particles outside  BenFRayfield  Physics  3  January 14th, 2015 10:19 PM 
Probability of a certain number of particles in spherical space  foothill  Advanced Statistics  1  October 13th, 2014 11:47 PM 
Kinematics of particles question, trig equation  jakeward123  Trigonometry  1  March 21st, 2012 07:03 AM 