A bar of soap (mass 0.1 kg) is sliding at 1.5 m/s, before smashing into a motionless bar of soap (mass 0.08 kg). After hitting each other, the soap sticks together and continues to slid. Ignore friction. what is the velocity of bars of soap after sticking together?

5/6 = 0.833

Explanation:

From conservation of momentum,

m1*u1  + m2*u2 =  (m1+m2)*v

v = (m1*u1 + m2*u2)/(m1*m2)

Putting in the values, we get, v = 5/6 = 0.833

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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