The 52Mg bus B is traveling to the right at 19 ms Meanwhile

The 5.2-Mg bus B is traveling to the right at 19 m/s. Meanwhile a 2-Mg car A is traveling at 12 m/s to the right. The Vehicles crash and become entangled. Assume that the vehicles are free to roll during collision. Determine their common velocity just after the collision. Express your answer to three significant figures and include the appropriate units.

Solution

Mass of bus = 5.2*10^3 kg = 5200 kg

Mass of car = 2*10^3 kg = 2000 kg

Momentum of bus = 5200*19 = 98800 kg-m/s

Momentum of car = 2000*12 = 24000 kg-m/s

Total initial momentum = 98800 + 24000 = 122800 kg-m/s

Total mass of car+bus = 5200 + 2000 = 7200 kg

Total momentum of car+bus = 7200*V.....where V is the common velocity after collision

By momentum conservation before and after the collision,

7200*V = 122800

V = 17.055 m/s