Exam 8: Momentum,impulse,and Collisions

A firecracker breaks up into several pieces,one of which has a mass of 200 g and flies off along the x-axis with a speed of 82.0 m/s.A second piece has a mass of 300 g and flies off along the y-axis with a speed of 45.0 m/s.What are the magnitude and direction of the total momentum of these two pieces?

A plate falls vertically to the floor and breaks up into three pieces,which slide along the floor.Immediately after the impact,a 320-g piece moves along the x-axis with a speed of 2.00 m/s and a 355-g piece moves along the y-axis with a speed of 1.50 m/s.The third piece has a mass of 100 g.In what direction does the third piece move? You can neglect any horizontal forces during the crash.

A stationary 1.67-kg object is struck by a stick.The object experiences a horizontal force given by F = at - bt²,where t is the time in milliseconds from the instant the stick first contacts the object.If a = 1500 N/(ms)and b = 20 N/(ms)²,what is the speed of the object just after it comes away from the stick at t = 2.74 ms?

You are standing on a skateboard,initially at rest.A friend throws a very heavy ball towards you.You can either catch the object or deflect the object back towards your friend (such that it moves away from you with the same speed as it was originally thrown).What should you do in order to MINIMIZE your speed on the skateboard?

In the figure,four point masses are placed as shown.The x and y coordinates of the center of mass are closest to

A 1.2-kg spring-activated toy bomb slides on a smooth surface along the x-axis with a speed of 0.50 m/s.At the origin 0,the bomb explodes into two fragments.Fragment 1 has a mass of 0.40 kg and a speed of 0.90 m/s along the negative y-axis.In the figure,the energy released by the explosion is closest to

Consider two less-than-desirable options.In the first you are driving 30 mph and crash head-on into an identical car also going 30 mph.In the second option you are driving 30 mph and crash head-on into a stationary brick wall.In neither case does your car bounce off the thing it hits,and the collision time is the same in both cases.Which of these two situations would result in the greatest impact force?

On a frictionless horizontal table,two blocks (A of mass 2.00 kg and B of mass 3.00 kg)are pressed together against an ideal massless spring that stores 75.0 J of elastic potential energy.The blocks are not attached to the spring and are free to move free of it once they are released from rest.The maximum speed achieved by each block is closest to

As a tile falls from the roof of a building to the ground its momentum is conserved.

A 900-kg car traveling east at 15.0 m/s collides with a 750-kg car traveling north at 20.0 m/s.The cars stick together.Assume that any other unbalanced forces are negligible. (a)What is the speed of the wreckage just after the collision? (b)In what direction does the wreckage move just after the collision?