Physics
posted by Mark .
A 0.1kg object is traveling to the right (in the positive direction) with a speed of 2 m/s. After a 0.2 s collision, the object is traveling to the left at 3 m/s. What is the magnitude of the impulse (in Ns) acting on the object? The answer must be positive.

Mass x (velocity change) = 0.1 x 5 kg m/s
= 0.5 N s
(1 kg m/s is the same as 1 N*s)
The duration of the collision doesn't matter in oomputing the impulse, but it does determine the force involved. 
a horizontal force of 100N is used to push a 20 kg box across a level floor for 10 m. how much work is done? how much work is needed to raise the same box by 10m?

20,000

20000