A white go-kart moving 5 m/s hits a red go-kart that is at rest. Both go-karts weigh 2 kilograms and the white go-kart travels in the opposite direction at 2 m/s after the collision. What is the velocity of the red
go-kart after the collision?
10 m/s
7 m/s
5 m/s
2 m/s

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.