A 5.8 x 104 kg train car at rest is struck from behind by a second train car, traveling at 2.6 m/s. The collision is completely inelastic so the cars stick together. The mass of the second car is 7.4 x 104 kg. What is the velocity of the joined trains cars immediately after the collision?
Round your answer to the tenths place.

One hazard of space travel is debris left by previous missions. there are several thousand masses large enough to detect by radar orbiting the earth, but there are far greater numbers of very small masses such as flakes of paint. calculate the force exerted by a 0.110 mg chip of paint that strikes a space shuttle window at a relative speed of 5.00 ✕ 103 m/s and sticks, given the collision lasts 6.00 ✕ 10-8 s. such a collision chipped the window of the ill-fated challenger in june 1983, causing $50,000 of damage.