
Splung.com Physics Forum Discuss physics or ask questions. Part of the Splung.com physics web site.

View previous topic :: View next topic 
Author 
Message 
flores101
Joined: 28 Feb 2011 Posts: 1 Location: canada

Posted: Mon Feb 28, 2011 1:52 am Post subject: minimum stopping distance 


A load of steel of mass 6,235 kg rests on the flatbed of a truck. It is held in place by metal brackets that can exert a maximum horizontal force of 7,974 N. When the truck is traveling 20 m/s, what is the minimum stopping distance if the load is not to slide forward into the cab? 

Back to top 


hepcj Site Admin
Joined: 23 Jun 2007 Posts: 125

Posted: Thu Mar 03, 2011 6:51 pm Post subject: 


This question requires that you know that force is the rate of change of acceleration and the equations of linear motion. You know maximum force before the brackets will break and the mass of the steel they are stopping from moving. So using
F = m a
you can calculate the acceleration a. In this case it is a deceleration so it is given a negative sign.
Then using the equations of motion to calculate the time taken to stop.
v= u + a t.
Where v is the final velocity i.e. = 0 m/s and u is the initial velocity = 20 m/s
From this you can calculate the time t.
Finally, to find the stopping distance s substitute the known information in
s = u t + 1/2 a t^2
and this will give you stopping distance.
I got an answer of 156 m (156.4) 

Back to top 




You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum

© Copyright 2010 Splung.com
