vectors at t<0
I have the following information:
A particle A of mass m is moving along a smooth horizontal surface with velocity of 2i + 3j. A second particle of mass 3m is moving with velocity 6i - 5j, collides with A at the origin at t=0. After this the particles coalesce.
Find the expressions of Ra(t) and Rb(t), the respective position vectors of the particles A and B at time <0. Hence find the position vector of the centre of mass of the system before the collision. Hence determine the velocity of the centre of mass.
how do i go about this?
This question links rather nicely with the one in this thread: http://www.mathhelpforum.com/math-he...-momentum.html
Originally Posted by thermalwarrior
so im correct in understanding from that reply the conditions at t=0 will hold for t<0?
to find the centre of mass of the system could i assume that the two particles are joined some kind of rod to make the system whole or can i just use the equation for centre of mass:
r = m1r1 + m2r2/m1+m2
then differentiate the position vector to find the velocity???