I need help on these 2 questions. 1) What impulse if needed to stop a 100kg mass traveling at a velocity of -25m/s? and 3) A force with a magnitude of 430 N is used to stop an object with a mass of 45kg moving at a velocity of 900m/s. How long will it take to bring the object to a full stop? -Any help on formulas and how to solve this would be appreciated.. Thanx!