In elastic collisions, total kinetic energy and momentum are both conserved. On a frictionless track, cart 1 is moving with a constant, rightward(+) velocity of 1.0m/s. Cart 2 is also moving rightward with constant velocity of 5.0m/s. After a while, cart 2 collides cart 1 from behind.(It is an elactic collision.)If the final velocity of cart 2 becomes 3.0m/s, what is the final velocity of cart 1?(SHOW ALL YOUR WORK.)

Explanation:

mass of cart 1, m1 = m

mass of cart 2, m2 = m

initial velocity of cart 1, u1 = 1 m/s

initial velocity of cart 2, u2 = 5 m/s

final velocity of cart 2, v2 = 3 m/s  

Let the final velocity of cart 1 is v1.

Use the conservation of momentum

m1 x u1 + m2 x u2 = m1 x v1 + m2 x v2

m x 1 + m x 5 = m x v1 + m x 3

6 = v1 + 3

v1 = 3 m/s

according to jean piaget, in what stage of cognitive development are children able to understand conservation task?

b. preoperational

just took it