Physics Help Forum Kinematics help!?

 Kinematics and Dynamics Kinematics and Dynamics Physics Help Forum

 Nov 19th 2015, 06:43 PM #1 Junior Member   Join Date: Nov 2015 Posts: 2 Kinematics help!? A student is late to the city bus. The bus starts from rest and begins to leave the stop at an acceleration of 1m/sē. The student turns the corner and sees the bus leaving 20m ahead of them. What is the smallest constant velocity with which the student will need to run to JUST catch the bus before it accelerates away too fast to intercept. (the bus never stops accelerating, the student just needs to intercept the bus.)
 Nov 20th 2015, 04:38 AM #2 Physics Team     Join Date: Jun 2010 Location: Morristown, NJ USA Posts: 2,347 You can set up two equations in two unknowns, then solve for those unknowns. First you have the fact that the student and bus must be at the same place at the same time. Let's call the student's velocity 'v' and the time it takes to catch the bus 't' - the equation that has them at the same place at the same time is: vt = 20 + (1/2)at^2 The second condition is that the student just barely catch the bus before it accelerates away - this is equivalent to saying that at the moment the student reaches the bus the velocity of the student = the velocity of the bus: v = at You know the value for 'a', so now you can solve for 'v' and 't'.

 Thread Tools Display Modes Linear Mode

 Similar Physics Forum Discussions Thread Thread Starter Forum Replies Last Post amit6234623 Kinematics and Dynamics 1 Oct 8th 2015 06:13 AM Aladdin Kinematics and Dynamics 8 Apr 3rd 2011 11:08 AM hah842 Kinematics and Dynamics 2 Sep 24th 2010 08:31 AM Fazil Kinematics and Dynamics 5 Mar 20th 2009 11:47 AM devanlevin Kinematics and Dynamics 0 Nov 17th 2008 09:25 AM