[s.a.l.m.a.n]

بسم الله الرحمن الرحيم

السلام عليكم ورحمة الله وبركاته

Mamentum and impulse



1) When a ball is hit with a given force , why does contact over a long time impart more speed to the ball??



2) Which undergoes the greatest change in momentum :



A) a baseball that is caught

B) a baseball that is thrown or

c) a baseball that is caught and then thrown back ,

if all of the baseballs have the same speed just befor being caught and just after being thrown



3) Railroad car A rolls at a certain speed and makes aperfectly elastic collision with car B of the same mass .After the collision . car A is observed to be at rest . How does the speed of car B compare with the initial speed of car A ?



4) To bring a supertanker to a stop , its engines are typicaaly cut off about 25 Km from port . Why is it so diffcult to stop or turn a supertanker??



5) In terms of impules and momentum , why do airbags in cars reduce chances of injury in accidets?



6) Your Friend says that he law of momentum conservation is violated when a ball rolls down a hill and gains momentum . What do you say??