# Momentum

• Sep 1st 2012, 10:06 PM
srirahulan
Momentum
Hi Guys, I have question on momentum.

A 2000 kg automobile going east on chestnut street at 60mi/hr collides with a 4000kg truck which is going south across chestnut street at 20mi/hr.If they become coupled
on collision, what is the magnitude and direction of their velocity immediately after colliding?

In this case we want to use conservation of linear Momentum.But i have a struggle on their velocity because it is a vector equation, So how can i find their velocity in proper way.
• Sep 2nd 2012, 07:53 AM
srirahulan
Re: Momentum
can any one understand my problem?
• Sep 2nd 2012, 09:00 AM
skeeter
Re: Momentum
Quote:

Originally Posted by srirahulan
can any one understand my problem?

momentum is conserved in both the x and y directions
• Sep 2nd 2012, 09:28 AM
srirahulan
Re: Momentum
Thanks for your solution but,How can i apply the equation for that.
• Sep 2nd 2012, 01:21 PM
skeeter
Re: Momentum
Quote:

Originally Posted by srirahulan
Thanks for your solution but,How can i apply the equation for that.

in the x-direction ...

$p_x_0 = p_x_f$

$2000(60) = (2000+4000)v_x_f$

in the y-direction ...

$p_y_0 = p_y_f$

$4000(-20) = (2000+4000)v_y_f$

... solve for the final velocity using the equations for each component of final velocity determined by the conservation of momentum equations above.