College Physics 9th Edition solutions

College Physics 9
A soccer player runs up behind a 0.450-kg soccer ball traveling at 3.20 m/s and kicks it in the same direction as it is moving, increasing its speed to 12.8 m/s. What magnitude impulse did the soccer player deliver to the ball? (a) 2.45 kg ? m/s (b) 4.32 kg ? m/s (c) 5.61 kg ? m/s (d) 7.08 kg ? m/s (

College Physics 9
A small china bowl having kinetic energy E is sliding along a frictionless countertop when a server, with perfect timing, places a rice ball into the bowl as it passes him. If the bowl and rice ball have the same mass, what is the kinetic energy of the system thereafter? (a) 2E (b) E (c) E/2 (d) E/4

College Physics 9
A car of mass m traveling at speed v crashes into the rear of a truck of mass 2m that is at rest and in neutral at an intersection. If the collision is perfectly inelastic, what is the speed of the combined car and truck after the collision? (a) v (b) v/2 (c) v/3 (d) 2v (e) None of these

College Physics 9
A 57.0-g tennis ball is traveling straight at a player at 21.0 m/s. The player volleys the ball straight back at 25.0 m/s. If the ball remains in contact with the racket for 0.060 s, what average force acts on the ball? (a) 22.6 kg ? m/s2 (b) 32.5 kg ? m/s2 (c) 43.7 kg ? m/s2 (d) 72.1 kg ? m/s2 (e) 1

College Physics 9
In a game of billiards, a red billiard ball is traveling in the positive x-direction with speed v and the cue ball is traveling in the negative x-direction with speed 3v when the two balls collide head on. Which statement is true concerning their velocities subsequent to the collision? Neglect any ef

College Physics 9
A 5-kg cart moving to the right with a velocity of 16 m/s collides with a concrete wall and rebounds with a velocity of 22 m/s. Is the change in momentum of the cart (a) 0, (b) 40 kg ? m/s, (c) 240 kg ? m/s, (d) 230 kg ? m/s, or (e) 210 kg ? m/s?

College Physics 9
A 2-kg object moving to the right with a speed of 4 m/s makes a head-on elastic collision with a 1-kg object that is initially at rest. The velocity of the 1-kg object after the collision is (a) greater than 4 m/s, (b) less than 4 m/s, (c) equal to 4 m/s, (d) zero, or (e) impossible to say based on t

College Physics 9
A 3-kg object moving to the right on a frictionless horizontal surface with a speed of 2 m/s collides head on and sticks to a 2-kg object that is initially moving to the left with a speed of 4 m/s. After the collision, which statement is true? (a) the kinetic energy of the system is 20 J, (b) the mom

College Physics 9
If two particles have equal kinetic energies, are their momenta equal? (a) yes, always (b) no, never (c) yes, as long as their masses are equal (d) yes, if both their masses and directions of motion are the same (e) no, unless they are moving perpendicular to each other

College Physics 9
If two particles have equal momenta, are their kinetic energies equal? (a) yes, always (b) no, never (c) no, except when their masses are equal (d) no, except when their speeds are the same (e) yes, as long as they move along parallel lines

College Physics 9
The kinetic energy of a rocket is increased by a factor of eight after its engines are fired, whereas its total mass is reduced by half through the burning of fuel. By what factor is the magnitude of its momentum changed? Hint: Use KE 5 p2/2m. (a) 2 (b) 8 (c) 4 (d) 16 (e) 1

College Physics 9
A rocket with total mass 3.00 3 105 kg leaves a launch pad at Cape Kennedy, moving vertically with an acceleration of 36.0 m/s2. If the speed of the exhausted gases is 4.50 3 103 m/s, at what rate is the rocket initially burning fuel? (a) 3.05 3 103 kg/s (b) 2.40 3 103 kg/s (c) 7.50 3 102 kg/s (d) 1.

College Physics 9
Two particles of different mass start from rest. The same net force acts on both of them as they move over equal distances. How do their final kinetic energies compare? (a) The particle of larger mass has more kinetic energy. (b) The particle of smaller mass has more kinetic energy. (c) The particles

College Physics 9
An open box slides across a frictionless, icy surface of a frozen lake. What happens to the speed of the box as water from a rain shower falls vertically downward into the box? Explain.

College Physics 9
Does a larger net force exerted on an object always produce a larger change in the momentum of the object, compared to a smaller net force? Explain.

College Physics 9
Does a larger net force always produce a larger change in kinetic energy than a smaller net force? Explain.

College Physics 9
The forces shown in the force vs. time diagram in Figure P6.17 act on a 1.5-kg particle. Find (a) the impulse for the interval from t 5 0 to t 5 3.0 s and (b) the impulse for the interval from t 5 0 to t 5 5.0 s. If the forces act on a 1.5-kg particle that is initially at rest, find the particles spe

College Physics 9
A 3.00-kg steel ball strikes a massive wall at 10.0 m/s at an angle of u 5 60.0 with the plane of the wall. It bounces off the wall with the same speed and angle (Fig. P6.18). If the ball is in contact with the wall for 0.200 s, what is the average force exerted by the wall on the ball?

College Physics 9
The front 1.20 m of a 1 400-kg car is designed as a crumple zone that collapses to absorb the shock of a collision. If a car traveling 25.0 m/s stops uniformly in 1.20 m, (a) how long does the collision last, (b) what is the magnitude of the average force on the car, and (c) what is the acceleration

College Physics 9
A pitcher throws a 0.14-kg baseball toward the batter so that it crosses home plate horizontally and has a speed of 42 m/s just before it makes contact with the bat. The batter then hits the ball straight back at the pitcher with a speed of 48 m/s. Assume the ball travels along the same line leaving

College Physics 9
High-speed stroboscopic photographs show that the head of a 200-g golf club is traveling at 55 m/s just before it strikes a 46-g golf ball at rest on a tee. After the collision, the club head travels (in the same direction) at 40 m/s. Find the speed of the golf ball just after impact.

College Physics 9
A rifle with a weight of 30 N fires a 5.0-g bullet with a speed of 300 m/s. (a) Find the recoil speed of the rifle. (b) If a 700-N man holds the rifle firmly against his shoulder, find the recoil speed of the man and rifle.

College Physics 9
A 45.0-kg girl is standing on a 150-kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface. The girl begins to walk along the plank at a constant velocity of 1.50 m/s to the right relative to the plank. (a) What is her velocity relative to th

College Physics 9
This is a symbolic version of Problem 23. A girl of mass mG is standing on a plank of mass mP. Both are originally at rest on a frozen lake that constitutes a frictionless, flat surface. The girl begins to walk along the plank at a constant velocity vGP to the right relative to the plank. (The subscr

College Physics 9
An astronaut in her space suit has a total mass of 87.0 kg, including suit and oxygen tank. Her tether line loses its attachment to her spacecraft while shes on a spacewalk. Initially at rest with respect to her spacecraft, she throws her 12.0-kg oxygen tank away from her spacecraft with a speed of 8

College Physics 9
A \(75 \mathrm{~kg}\) fisherman in a 125-kg boat throws a package of mass \(m=15 \mathrm{~kg}\) horizontally toward the right with a speed of \(v_{i}=4.5 \mathrm{~m} / \mathrm{s}\) as in Figure P6.26. Neglecting water resistance, and assuming the boat is at rest before the package is thrown, find the

College Physics 9
A 65.0-kg person throws a 0.045 0-kg snowball forward with a ground speed of 30.0 m/s. A second person, with a mass of 60.0 kg, catches the snowball. Both people are on skates. The first person is initially moving forward with a speed of 2.50 m/s, and the second person is initially at rest. What are

College Physics 9
An amateur skater of mass M (when fully dressed) is trapped in the middle of an ice rink and is unable to return to the side where there is no ice. Every motion she makes causes her to slip on the ice and remain in the same spot. She decides to try to return to safety by removing her gloves of mass m

College Physics 9
A man of mass m1 5 70.0 kg is skating at v1 5 8.00 m/s behind his wife of mass m2 5 50.0 kg, who is skating at v2 5 4.00 m/s. Instead of passing her, he inadvertently collides with her. He grabs her around the waist, and they maintain their balance. (a) Sketch the problem with before-and-after diagra

College Physics 9
An archer shoots an arrow toward a 300-g target that is sliding in her direction at a speed of 2.50 m/s on a smooth, slippery surface. The 22.5-g arrow is shot with a speed of 35.0 m/s and passes through the target, which is stopped by the impact. What is the speed of the arrow after passing through

College Physics 9
Gayle runs at a speed of 4.00 m/s and dives on a sled, initially at rest on the top of a frictionless, snow- covered hill. After she has descended a vertical distance of 5.00 m, her brother, who is initially at rest, hops on her back, and they continue down the hill together. What is their speed at t

College Physics 9
A 75.0-kg ice skater moving at 10.0 m/s crashes into a stationary skater of equal mass. After the collision, the two skaters move as a unit at 5.00 m/s. Suppose the average force a skater can experience without breaking a bone is 4 500 N. If the impact time is 0.100 s, does a bone break?

College Physics 9
A railroad car of mass 2.00 3 104 kg moving at 3.00 m/s collides and couples with two coupled railroad cars, each of the same mass as the single car and moving in the same direction at 1.20 m/s. (a) What is the speed of the three coupled cars after the collision? (b) How much kinetic energy is lost i

College Physics 9
This is a symbolic version of Problem 33. A railroad car of mass M moving at a speed v1 collides and couples with two coupled railroad cars, each of the same mass M and moving in the same direction at a speed v2. (a) What is the speed vf of the three coupled cars after the collision in terms of v1 an

College Physics 9
Consider the ballistic pendulum device discussed in Example 6.5 and illustrated in Figure 6.12. (a) Determine the ratio of the momentum immediately after the collision to the momentum immediately before the collision. (b) Show that the ratio of the kinetic energy immediately after the collision to th

College Physics 9
A car of mass m moving at a speed v1 collides and couples with the back of a truck of mass 2m moving initially in the same direction as the car at a lower speed v2. (a) What is the speed vf of the two vehicles immediately after the collision? (b) What is the change in kinetic energy of the cartruck s

College Physics 9
In a Broadway performance, an 80.0-kg actor swings from a 3.75-m-long cable that is horizontal when he starts. At the bottom of his arc, he picks up his 55.0-kg costar in an inelastic collision. What maximum height do they reach after their upward swing?

College Physics 9
Two shuffleboard disks of equal mass, one orange and the other green, are involved in a perfectly elastic glancing collision. The green disk is initially at rest and is struck by the orange disk moving initially to the right at 5.00 m/s as in Figure P6.38a. After the collision, the orange disk moves

College Physics 9
A 0.030-kg bullet is fired vertically at 200 m/s into a 0.15-kg baseball that is initially at rest. How high does the combined bullet and baseball rise after the collision, assuming the bullet embeds itself in the ball?

College Physics 9
An bullet of mass m = 8.00 g is fired into a block of mass M = 250 g that is initially at rest at the edge of a table of height h 5 1.00 m (Fig. P6.40). The bullet remains in the block, and after the impact the block lands d = 2.00 m from the bottom of the table. Determine the initial speed of the bu

College Physics 9
A 12.0-g bullet is fired horizontally into a 100-g wooden block that is initially at rest on a frictionless horizontal surface and connected to a spring having spring constant 150 N/m. The bullet becomes embedded in the block. If the bulletblock system compresses the spring by a maximum of 80.0 cm, w

College Physics 9
A 1 200-kg car traveling initially with a speed of 25.0 m/s in an easterly direction crashes into the rear end of a 9 000-kg truck moving in the same direction at 20.0 m/s (Fig. P6.42 on page 194). The velocity of the car right after the collision is 18.0 m/s to the east. (a) What is the velocity of

College Physics 9
A boy of mass mb and his girlfriend of mass mg, both wearing ice skates, face each other at rest while standing on a frictionless ice rink. The boy pushes the girl, sending her away with velocity vg toward the east. Assume that mb . mg. (a) Describe the subsequent motion of the boy. (b) Find expressi

College Physics 9
A space probe, initially at rest, undergoes an internal mechanical malfunction and breaks into three pieces. One piece of mass m1 5 48.0 kg travels in the positive x-direction at 12.0 m/s, and a second piece of mass m2 5 62.0 kg travels in the xy-plane at an angle of 105 at 15.0 m/s. The third piece

College Physics 9
A 25.0-g object moving to the right at 20.0 cm/s overtakes and collides elastically with a 10.0-g object moving in the same direction at 15.0 cm/s. Find the velocity of each object after the collision.

College Physics 9
A billiard ball rolling across a table at 1.50 m/s makes a head-on elastic collision with an identical ball. Find the speed of each ball after the collision (a) when the second ball is initially at rest, (b) when the second ball is moving toward the first at a speed of 1.00 m/s, and (c) when the seco

College Physics 9
A 90.0-kg fullback running east with a speed of 5.00 m/s is tackled by a 95.0-kg opponent running north with a speed of 3.00 m/s. (a) Why does the tackle constitute a perfectly inelastic collision? (b) Calculate the velocity of the players immediately after the tackle and (c) determine the mechanical

College Physics 9
Identical twins, each with mass 55.0 kg, are on ice skates and at rest on a frozen lake, which may be taken as frictionless. Twin A is carrying a backpack of mass 12.0 kg. She throws it horizontally at 3.00 m/s to Twin B. Neglecting any gravity effects, what are the subsequent speeds of Twin A and Tw

College Physics 9
A 2 000-kg car moving east at 10.0 m/s collides with a 3 000-kg car moving north. The cars stick together and move as a unit after the collision, at an angle of 40.0 north of east and a speed of 5.22 m/s. Find the speed of the 3 000-kg car before the collision.

College Physics 9
Two automobiles of equal mass approach an intersection. One vehicle is traveling with velocity 13.0 m/s toward the east, and the other is traveling north with velocity v2i. Neither driver sees the other. The vehicles collide in the intersection and stick together, leaving parallel skid marks at an an

College Physics 9
A billiard ball moving at 5.00 m/s strikes a stationary ball of the same mass. After the collision, the first ball moves at 4.33 m/s at an angle of 30 with respect to the original line of motion. (a) Find the velocity (magnitude and direction) of the second ball after collision. (b) Was the collision

College Physics 9
In research in cardiology and exercise physiology, it is often important to know the mass of blood pumped by a persons heart in one stroke. This information can be obtained by means of a ballistocardiograph. The instrument works as follows: The subject lies on a horizontal pallet floating on a film o

College Physics 9
Most of us know intuitively that in a head-on collision between a large dump truck and a subcompact car, you are better off being in the truck than in the car. Why is this? Many people imagine that the collision force exerted on the car is much greater than that exerted on the truck. To substantiate

College Physics 9
Consider a frictionless track as shown in Figure P6.54. A block of mass m1 5 5.00 kg is released from _. It makes a head-on elastic collision at _ with a block of mass m2 5 10.0 kg that is initially at rest. Calculate the maximum height to which m1 rises after the collision. m1 m2 5.00 m _ _ Figure P

College Physics 9
A 2.0-g particle moving at 8.0 m/s makes a perfectly elastic head-on collision with a resting 1.0-g object. (a) Find the speed of each particle after the collision. (b) Find the speed of each particle after the collision if the stationary particle has a mass of 10 g. (c) Find the final kinetic energy

College Physics 9
A bullet of mass m and speed v passes completely through a pendulum bob of mass M as shown in Figure P6.56. The bullet emerges with a speed of v/2. The pendulum bob is suspended by a stiff rod of length , and neglim gible mass. What is the minimum value of v such that the bob will barely swing throug

College Physics 9
Two objects of masses \(m_1=0.56\mathrm{\ kg}\) and \(m_2=0.88\mathrm{\ kg}\) are placed on a horizontal frictionless surface and a compressed spring of force constant \(\mathrm{k}=280\mathrm{\ N}/\mathrm{m}\) is placed between them as in Figure P6.57a. Neglect the mass of the spring. The spring is n

College Physics 9
A 0.400-kg blue bead slides on a frictionless, curved wire, starting from rest at point _ in Figure P6.58, where h 5 1.50 m. At point _, the bead collides elastically with a 0.600-kg green bead at rest. Find the maximum height the green bead rises as it moves up the wire.

College Physics 9
A 730-N man stands in the middle of a frozen pond of radius 5.0 m. He is unable to get to the other side because of a lack of friction between his shoes and the ice. To overcome this difficulty, he throws his 1.2-kg physics textbook horizontally toward the north shore at a speed of 5.0 m/s. How long

College Physics 9
An unstable nucleus of mass 1.7 3 10226 kg, initially at rest at the origin of a coordinate system, disintegrates into three particles. One particle, having a mass of m1 5 5.0 3 10227 kg, moves in the positive y- direction with speed v1 5 6.0 3 106 m/s. Another particle, of mass m2 5 8.4 3 10227 kg,

College Physics 9
Two blocks of masses m1 and m2 approach each other on a horizontal table with the same constant speed, v0, as measured by a laboratory observer. The blocks undergo a perfectly elastic collision, and it is observed that m1 stops but m2 moves opposite its original motion with some constant speed, v. (a

College Physics 9
Two blocks of masses m1 5 2.00 kg and m2 5 4.00 kg are each released from rest at a height of h 5 5.00 m on a frictionless track, as shown in Figure P6.62 (page 196), and undergo an elastic head-on collision. (a) Determine the velocity of each block just before the collision. (b) Determine the veloci

College Physics 9
A block with mass m1 5 0.500 kg is released from rest on a frictionless track at a distance h1 5 2.50 m above the top of a table. It then collides elastically with an object having mass m2 5 1.00 kg that is initially at rest on the table, as shown in Figure P6.63. (a) Determine the velocities of the

College Physics 9
Two objects of masses m and 3m are moving toward each other along the x-axis with the same initial speed v0. The object with mass m is traveling to the left, and the object with mass 3m is traveling to the right. They undergo an elastic glancing collision such that m is moving downward after the coll

College Physics 9
A small block of mass m1 5 0.500 kg is released from rest at the top of a curved wedge of mass m2 5 3.00 kg, which sits on a frictionless horizontal surface as in Figure P6.65a. When the block leaves the wedge, its velocity is measured to be 4.00 m/s to the right, as in Figure P6.65b. (a) What is the

College Physics 9
A cue ball traveling at 4.00 m/s makes a glancing, elastic collision with a target ball of equal mass that is initially at rest. The cue ball is deflected so that it makes an angle of 30.0 with its original direction of travel. Find (a) the angle between the velocity vectors of the two balls after th

College Physics 9
A cannon is rigidly attached to a carriage, which can move along horizontal rails, but is connected to a post by a large spring, initially unstretched and with force constant k 5 2.00 3 104 N/m, as in Figure P6.67. The cannon fires a 200-kg projectile at a velocity of 125 m/s directed 45.0 above the

College Physics 9
The force platform is a tool that is used to analyze the performance of athletes by measuring the vertical force as a function of time that the athlete exerts on the ground in performing various activities. A simplified force vs. time graph for an athlete performing a standing high jump is shown in F

College Physics 9
A neutron in a reactor makes an elastic head-on collision with a carbon atom that is initially at rest. (The mass of the carbon nucleus is about 12 times that of the neutron.) (a) What fraction of the neutrons kinetic energy is transferred to the carbon nucleus? (b) If the neutrons initial kinetic en

College Physics 9
Two blocks collide on a frictionless surface. After the collision, the blocks stick together. Block A has a mass M and is initially moving to the right at speed v. Block B has a mass 2M and is initially at rest. System C is composed of both blocks. (a) Draw a force diagram for each block at an instan

College Physics 9
(a) A car traveling due east strikes a car traveling due north at an intersection, and the two move together as a unit. A property owner on the southeast corner of the intersection claims that his fence was torn down in the collision. Should he be awarded damages by the insurance company? Defend your

College Physics 9
A 60-kg soccer player jumps vertically upwards and heads the 0.45-kg ball as it is descending vertically with a speed of 25 m/s. (a) If the player was moving upward with a speed of 4.0 m/s just before impact, what will be the speed of the ball immediately after the collision if the ball rebounds vert

College Physics 9
A tennis ball of mass 57.0 g is held just above a basketball of mass 590 g. With their centers vertically aligned, both balls are released from rest at the same time, to fall through a distance of 1.20 m, as shown in Figure P6.73. (a) Find the magnitude of the downward velocity with which the basketb

College Physics 9
A 20.0-kg toboggan with 70.0-kg driver is sliding down a frictionless chute directed 30.0 below the horizontal at 8.00 m/s when a 55.0-kg woman drops from a tree limb straight down behind the driver. If she drops through a vertical displacement of 2.00 m, what is the subsequent velocity of the tobogg

College Physics 9
Measuring the speed of a bullet. A bullet of mass m is fired horizontally into a wooden block of mass M lying on a table. The bullet remains in the block after the collision. The coefficient of friction between the block and table is m, and the block slides a distance d before stopping. Find the init

College Physics 9
A flying squid (family Ommastrephidae) is able to jump off the surface of the sea by taking water into its body cavity and then ejecting the water vertically downward. A 0.85-kg squid is able to eject 0.30 kg of water with a speed of 20 m/s. (a) What will be the speed of the squid immediately after

College Physics 9
A 0.30-kg puck, initially at rest on a frictionless horizontal surface, is struck by a 0.20-kg puck that is initially moving along the x-axis with a velocity of 2.0 m/s. After the collision, the 0.20-kg puck has a speed of 1.0 m/s at an angle of u 5 53 to the positive x-axis. (a) Determine the veloci

College Physics 9
A wooden block of mass M rests on a table over a large hole as in Figure P6.78. A bullet of mass m with an initial velocity vi is fired upward into the bottom of the block and remains in the block after the collision. The block and bullet rise to a maximum height of h. (a) Describe how you would find

College Physics 9
A 1.25-kg wooden block rests on a table over a large hole as in Figure P6.78. A 5.00-g bullet with an initial velocity vi is fired upward into the bottom of the block and remains in the block after the collision. The block and bullet rise to a maximum height of 22.0 cm. (a) Describe how you would fin