Exam 6: Impulse and Linear Momentum

A 1000-kg whale swims horizontally to the right at a speed of 6.0 m/s.It suddenly collides directly with a stationary seal of mass 200 kg.The seal grabs onto the whale and holds fast.What is the speed of these two sea creatures just after their collision? You can neglect any drag effects of the water during the collision.

A car (of mass 1500 kg)and a small truck (of mass 2000 kg)collide suddenly at right angles at an icy intersection.The car was originally traveling eastward at 20.0 m/s and the truck was traveling northward at 20.0 m/s just before the collision took place.What is the speed of the combined wreck just after the collision if the vehicles become enmeshed?

A 0.24 kg blob of clay is thrown at a wall with an initial horizontal velocity of $16 \mathrm {~m} / \mathrm { s }$ If the clay comes to a stop in $91 \mathrm {~ms} \text {, }$ what is the average horizontal force exerted on the clay by the wall?

A girl of mass 55 kg throws a ball of mass 0.80 kg against a wall.The ball strikes the wall horizontally with a speed of $25 \mathrm {~m} / \mathrm { s } \text {, }$ and it bounces back with this same speed.The ball is in contact with the wall $0.050 \mathrm {~s} .$ What is the magnitude of the average force exerted on the wall by the ball?

A 0.10-kg ball,traveling horizontally at 25 m/s,strikes a wall and rebounds at 19 m/s.What is the magnitude of the change in the momentum of the ball during the rebound?

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 back from the thing it hits,and the collision time is the same in both cases.Which of these two situations would result in the greater impact force exerted on your car?

A 900-kg car traveling east at 15.0 m/s suddenly collides with a 750-kg car traveling north at 20.0 m/s.The cars stick together after the collision.What is the speed of the wreckage just after the collision?

A super dart of mass 20 g,traveling at 350 m/s,strikes a steel plate at an angle of 30° with the plane of the plate,as shown in the figure.It bounces off the plate at the same angle but at a speed of 320 m/s.What is the magnitude of the impulse that the plate exerts on the bullet?

A car heading north suddenly collides at an intersection with a truck of the same mass heading east.If they lock together and travel at $28 \mathrm {~m} / \mathrm { s }$ at 15° north of east just after the collision,how fast was the car initially traveling?

Which of the following quantities are units of impulse? (There could be more than one correct choice.)

A 1200-kg cannon suddenly fires a $\text { 100-kg }$ cannonball at $35 \mathrm {~m} / \mathrm { s }$ What is the recoil speed of the cannon? Assume that frictional forces are negligible and the cannon is fired horizontally.

Three cars,car X,car Y,and car Z,begin accelerating from rest at the same time.Car X is more massive than car Y,which is more massive than car Z.The net accelerating force exerted on each car is identical.After 10 seconds,which car has the most amount of momentum?

Jennifer hits a stationary 0.20-kg ball,and it leaves her racket at 40 m/s.Time-lapse photography shows that the ball was in contact with the racket for 40 ms. (a)What average force did the ball exert on the racket? (b)What is the ratio of this force to the gravitational force that Earth exerts on the ball?

A golf ball of mass 0.050 kg is at rest on the tee.Just after being struck,it has a velocity of 102 m/s.If the club and ball were in contact for $0.81 \mathrm {~ms} \text {, }$ what is the average force exerted on the ball by the club?

Two dogs,Rover and Fido,run on a level frictionless surface.Rover runs eastward with a momentum of 24 kg .m/s,and Fido runs northward with momentum 10 kg .m/s.They make a sudden perfectly inelastic collision.What is the magnitude of their combined momentum after the collision?

A fire hose is turned on the door of a burning building in order to knock the door down.This requires a force of 1000 N.If the hose delivers 40 kg of water per second,what is the minimum velocity of the stream needed to knock down the door,assuming the water doesn't bounce back?

A block of mass m = 34 kg and speed V is behind a block of mass M = 81 kg and speed of $0.50 \mathrm {~m} / \mathrm { s }$ as shown in the figure.The surface is frictionless and the blocks collide and couple.After the collision,the blocks have a common speed of $0.90 \mathrm {~m} / \mathrm { s }$ What is the magnitude of the impulse on the 34-kg block due to the collision?

A 1500-kg car traveling at 90 km/h toward the east suddenly collides with a 3000-kg car traveling at 60 km/h toward the south.The two cars stick together after the collision.What is the direction of motion of the cars after collision?

A 1200-kg ore cart is rolling at 10.8 m/s across a flat friction-free surface.A crane suddenly drops $858 \mathrm {~kg}$ of ore vertically into the cart.How fast does the cart move just after being loaded with the ore?

A batter hits a foul ball.The 0.14-kg baseball that was approaching him at 40 m/s leaves the bat at 30 m/s in a direction perpendicular to the line between the batter and the pitcher.What is the magnitude of the impulse exerted on the baseball?