physics problem?

Question

1. A 1550 kg car moving south at 12.2 m/s collides with a 2360 kg car moving north. The cars stick together and move as a unit after the collision at a velocity of 5.90 m/s to the north. Find the velocity of the 2360 kg car before the collision.

2. Two carts with masses of 4.92 kg and 2.56 kg move toward each other on a frictionless track with speeds of 5.43 m/s and 3.08 m/s respectively. The carts stick together after colliding head-on. Find the final speed.

Answer 1

#1Concervation of momentum
m1V1-m2V2= (m1+m2)V

V2=((m1+m2)V+m1V1)/m2
V2= ((1550 +2360) 5.90 + 1550x 12.2)/2360
V2=17.8 m/s (and we confirmed that it was north)

#2 Again
m1V1-m2V2= (m1+m2)V this time however solving for V we have
V=((m1V1-m2V2)/(m1+m2)
V=(4.92x5.43-2.56x3.08)/(4.92+2.56)
V=2.52 m/s (in the same direction as m1 before the collision)

Answer 2

This is a momentum question

The formula you want is
m1v1i + m2v2i = m1vf + m2vf

the final velocities are the same because they 'stick together'

for the first question:
v2i = [vf(m1+m2) - m1v1i] / m2
v2i = 17.8m/s north

for the second question

vf = (m1v1i + m2v2i) / (m1 + m2)
vf = 2.52m/s in the same direction of the first cart

although it just asks for the speed in the second question, so the correct answer is '2.52m/s' - no direction in speed

direction DOES matter in the first question, since it asks for velocity (which is a vector quantity)

=)

Answer 3

the galaxies rotate at speeds inconsistent with their obvious mass is via the fact we do see all of it. i'm relating it as being the theoretical darkish count number. There are very reliable proofs that shows that darkish count number exist. One the is the inconsistent speed of and obvious mass. darkish count number makes up approximately seventy 5% to eighty% of the problem interior the Universe...