An object has a mass of 40 kg and a velocity of 10m/s. It collides with two masses (each mass 40 kg) attached to each other and moving with a velocity of 2 m/s. All three objects are stuck together after collision. What is the velocity of the three masses after collision?
2007-11-25 09:58:29 · 1 answers · asked by Anonymous in Education & Reference ➔ Homework Help
For this, momentum is constant. Momentum, p, is the mass times the velocity. Before impact, you have an object with a mass and a velocity, and after impact, you have a larger mass and a smaller velocity. We can calculate the velocity of the new mass as follows:
m1v1 + m2v2 = m3v3
(40 kg)(10 m/s) + (80 kg)(2 m/s) = (120 kg)(v3)
400 kgm/s + 160 kgm/s = (120 kg)(v3)
560 kgm/s = (120 kg)(v3)
v3 = 4.67 m/s
This assumes that all masses are moving in a straight line, and m1 is basically rear-ending m2. The answer would be different if they were moving directly toward each other, and different still if impact was at an angle.
2007-11-25 17:49:35 · answer #1 · answered by igorotboy 7 · 0⤊ 0⤋