two carts resting on a frictionless surface are forced apart by a spring one cart hass masss of 2 kilograms?

Question

and moves to the left at a speed of 3m/s if the second cart has mass of 3 kilograms it will move to the right speed of/?

yes, i'm so proud i got the same answer thankyou for making it clear! :] and explaining why it is right...

Answer 1

Momentum must be conserved.

Initially, the carts are not moving, so the momentum is 0.

Afterwards the momentum (to the left) is

2*3 - 3V = 0
3V = 6

The speed of the second cart is 2 m/s

Answer 2

2 mps.

The momentum of the two masses before the spring is sprung is Mv + mV = 0 because V = v = 0, neither mass is moving. Afterwords we have Mv - mV = 0 because of the conservation of momentum. That is, the momenta after the spring is sprung has to equal the same momentum before the spring is sprung. The minus sign in this second term comes from the observation that the two velocities are headed in opposite (minus and plus) directions. Therefore we have Mv = mV and v = (m/M)V; where m = 2 kg, M = 3 kg, V = 3 mps, and v is the velocity you are looking for.