M A 6.0 kg wagon moving right at 3.0 on a frictionless track collides and sticks to a 4.0 kg wagon moving
S
m
left at 12
S
х
What is the final speed of the wagons?
Consider rightward as the positive direction.
Round answer to two significant digits.

Can someone explain to me how to do this problem ?

4. if you were an astronaut on the moon, what would you experience? what would you see from your perspective?

Along wire of diameter 1 mm is submerged in an oil bath of temperature ∞ 31°c. the wire has an electrical resistance per unit length of 0.01 ω/m. if a current of 103 a flows through the wire and the convection coefficient is 500 w/m2·k, what is the steady-state temperature of the wire? from the time the current is applied, how long does it take for the wire to reach a temperature that is within 1°c of the steady-state value? the properties of the wire are 8000 kg/m3, 500 j/kg·k, and 20 w/m·k.