Question: A truck tractor pulls two trailers, one

> To what extent does internalization theory explain Burberry’s experience in Japan?

> After falling from rest from a height of 30.0 m, a 0.500-kg ball rebounds upward, reaching a height of 20.0 m. If the contact between ball and ground lasted 2.00 ms, what average force was exerted on the ball?

> An object of mass m is dropped from the roof of a building of height h. While the object is falling, a wind blowing parallel to the face of the building exerts a constant horizontal force F on the object. (a) How long does it take the object to strike th

> A 970.-kg car starts from rest on a horizontal roadway and accelerates eastward for 5.00 s when it reaches a speed of 25.0 m/s. What is the average force exerted on the car during this time?

> Two forces are applied to a car in an effort to move it, as shown in Figure P4.12. (a) What is the resultant vector of these two forces? (b) If the car has a mass of 3000 kg, what acceleration does it have? Ignore friction. Figure P4.12

> A boat moves through the water with two forces acting on it. One is a 2.00 x 103-N forward push by the water on the propeller, and the other is a 1.80 x 103-N resistive force due to the water around the bow. (a) What is the acceleration of the 1.00 x 103

> A 5.0-g bullet leaves the muzzle of a rifle with a speed of 320 m/s. What force (assumed constant) is exerted on the bullet while it is traveling down the 0.82-m-long barrel of the rifle?

> The heaviest invertebrate is the giant squid, which is estimated to have a weight of about 2 tons spread out over its length of 70 feet. What is its weight in newtons?

> A 72-kg man stands on a spring scale in an elevator. Starting from rest, the elevator ascends, attaining its maximum speed of 1.2 m/s in 0.80 s. The elevator travels with this constant speed for 5.0 s, undergoes a uniform negative acceleration for 1.5 s,

> The board sandwiched between two other boards in Figure P4.91 weighs 95.5 N. If the coefficient of friction between the boards is 0.663, what must be the magnitude of the compression forces (assumed to be horizontal) acting on both sides of the center bo

> A fire helicopter carries a 620-kg bucket of water at the end of a 20.0-m-long cable. Flying back from a fire at a constant speed of 40.0 m/s, the cable makes an angle of 40.0° with respect to the vertical. Determine the force exerted by air resistance o

> If only one force acts on an object, can it be in equilibrium? Explain.

> The parachute on a race car of weight 8820 N opens at the end of a quarter-mile run when the car is traveling at 35.0 m/s. What total retarding force must be supplied by the parachute to stop the car in a distance of 1.00 x 103 m?

> An inventive child wants to reach an apple in a tree without climbing the tree. Sitting in a chair connected to a rope that passes over a frictionless pulley (Fig. P4.88), the child pulls on the loose end of the rope with such a force that the spring sca

> A car accelerates down a hill (Fig. P4.87), going from rest to 30.0 m/s in 6.00 s. During the acceleration, a toy (m = 0.100 kg) hangs by a string from the car’s ceiling. The acceleration is such that the string remains perpendicular to

> A sled weighing 60.0 N is pulled horizontally across snow so that the coefficient of kinetic friction between sled and snow is 0.100. A penguin weighing 70.0 N rides on the sled, as in Figure P4.86. If the coefficient of static friction between penguin a

> Two boxes of fruit on a frictionless horizontal surface are connected by a light string as in Figure P4.85, where m1 = 10.0 kg and m2 = 20.0 kg. A force of 50.0 N is applied to the 20.0-kg box. (a) Determine the acceleration of each box and the tension i

> On an airplane’s takeoff, the combined action of the air around the engines and wings of an airplane exerts an 8000-N force on the plane, directed upward at an angle of 65.0° above the horizontal. The plane rises with constant velocity in the vertical di

> A 2.00-kg aluminum block and a 6.00-kg copper block are connected by a light string over a frictionless pulley. The two blocks are allowed to move on a fixed steel block wedge (of angle θ = 30.0°) as shown in Figure P4.83. Making

> Measuring coefficients of friction A coin is placed near one edge of a book lying on a table, and that edge of the book is lifted until the coin just slips down the incline as shown in Figure P4.82. The angle of the incline, θc, called the c

> A frictionless plane is 10.0 m long and inclined at 35.0°. A sled starts at the bottom with an initial speed of 5.00 m/s up the incline. When the sled reaches the point at which it momentarily stops, a second sled is released from the top of the incline

> A high diver of mass 70.0 kg steps off a board 10.0 m above the water and falls vertical to the water, starting from rest. If her downward motion is stopped 2.00 s after her feet first touch the water, what average upward force did the water exert on her

> A ball is thrown upward in the air by a passenger on a train that is moving with constant velocity. (a) Describe the path of the ball as seen by the passenger. Describe the path as seen by a stationary observer outside the train. (b) How would these obse

> A box rests on the back of a truck. The coefficient of static friction between the box and the bed of the truck is 0.300. (a) When the truck accelerates forward, what force accelerates the box? (b) Find the maximum acceleration the truck can have before

> Three objects are connected by light strings as shown in Figure P4.78. The string connecting the 4.00-kg object and the 5.00-kg object passes over a light frictionless pulley. Determine (a) The acceleration of each object and (b) The tension in the two s

> A boy coasts down a hill on a sled, reaching a level surface at the bottom with a speed of 7.00 m/s. If the coefficient of friction between the sled’s runners and the snow is 0.050 0 and the boy and sled together weigh 600. N, how far does the sled trave

> Choose the best answer. A car traveling at constant speed has a net force of zero acting on it. (a) True (b) False (c) The answer depends on the motion.

> A woman is standing on the Earth. In terms of magnitude, is her gravitational force on the Earth (a) Equal to, (b) Less than, or (c) Greater than the Earth’s gravitational force on her?

> A large crate of mass m is placed on the back of a truck but not tied down. As the truck accelerates forward with an acceleration a, the crate remains at rest relative to the truck. What force causes the crate to accelerate forward? (a) The normal force

> If an object is in equilibrium, which of the following statements is not true? (a) The speed of the object remains constant. (b) The acceleration of the object is zero. (c) The net force acting on the object is zero. (d) The object must be at rest. (e) T

> A crate remains stationary after it has been placed on a ramp inclined at an angle with the horizontal. Which of the following statements must be true about the magnitude of the frictional force that acts on the crate? (a) It is larger than the weight of

> A stuntman sitting on a tree limb wishes to drop vertically onto a horse galloping under the tree. The constant speed of the horse is 10.0 m/s, and the man is initially 3.00 m above the level of the saddle. (a) What must be the horizontal distance betwee

> In Bosnia, the ultimate test of a young man’s courage used to be to jump off a 400 - year - old bridge (destroyed in 1993; rebuilt in 2004) into the River Neretva, 23 m below the bridge. (a) How long did the jump last? (b) How fast was the jumper traveli

> A weightlifter stands on a bathroom scale. (a) As she pumps a barbell up and down, what happens to the reading on the scale? (b) Suppose she is strong enough to actually throw the barbell upward. How does the reading on the scale vary now?

> One of Aesop’s fables tells of a race between a tortoise and a hare. Suppose the overconfident hare takes a nap and wakes up to find the tortoise a distance d ahead and a distance L from the finish line. If the hare then begins running with constant spee

> A mountain climber stands at the top of a 50.0 - m cliff that overhangs a calm pool of water. She throws two stones vertically downward 1.00 s apart and observes that they cause a single splash. The first stone had an initial velocity of -2.00 m/s. (a) H

> Emily challenges her husband, David, to catch a $1 bill as follows. She holds the bill vertically as in Figure P2.67, with the center of the bill between David’s index finger and thumb. David must catch the bill after Emily releases it

> The thickest and strongest chamber in the human heart is the left ventricle, responsible during systole for pumping oxygenated blood through the aorta to rest of the body. Assume aortic blood starts from rest and accelerates at 22.5 m/s2 to a peak speed

> A ball thrown straight up into the air is found to be moving at 1.50 m/s after rising 2.00 m above its release point. Find the ball’s initial speed.

> A player holds two baseballs a height h above the ground. He throws one ball vertically upward at speed υ0 and the other vertically downward at the same speed. Calculate (a) The speed of each ball as it hits the ground and (b) The difference between thei

> A ball is thrown upward from the ground with an initial speed of 25 m/s; at the same instant, another ball is dropped from a building 15 m high. After how long will the balls be at the same height?

> An object is moving in the positive direction along the x - axis. Sketch plots of the object’s position vs. time and velocity vs. time if (a) its speed is constant, (b) it’s speeding up at a constant rate, and (c) it’s slowing down at a constant rate.

> An insect called the froghopper (Philaenus spumarius) has been called the best jumper in the animal kingdom. This insect can accelerate at over 4.0 x 103 m/s2 during a displacement of 2.0 mm as it straightens its specially equipped “jumping legs.” (a) As

> Mature salmon swim upstream, returning to spawn at their birthplace. During the arduous trip they leap vertically upward over waterfalls as high as 3.6 m. With what minimum speed must a salmon launch itself into the air to clear a 3.6 - m waterfall?

> Determine which of the following moving objects obey the equations of projectile motion developed in this topic. (a) A ball is thrown in an arbitrary direction. (b) A jet airplane crosses the sky with its engines thrusting the plane forward. (c) A rocket

> A student throws a set of keys vertically upward to his fraternity brother, who is in a window 4.00 m above. The brother’s outstretched hand catches the keys 1.50 s later. (a) With what initial velocity were the keys thrown? (b) What was the velocity of

> A speedboat moving at 30.0 m/s approaches a no-wake buoy marker 1.00 x 102 m ahead. The pilot slows the boat with a constant acceleration of -3.50 m/s2 by reducing the throttle. (a) How long does it take the boat to reach the buoy? (b) What is the veloci

> A bullet is fired through a board 10.0 cm thick in such a way that the bullet’s line of motion is perpendicular to the face of the board. If the initial speed of the bullet is 4.00 x 102 m/s and it emerges from the other side of the board with a speed of

> Colonel John P. Stapp, USAF, participated in studying whether a jet pilot could survive emergency ejection. On March 19, 1954, he rode a rocket- propelled sled that moved down a track at a speed of 632 mi/h (see Fig. P2.56). He and the sled were safely b

> A baseball is hit so that it travels straight upward after being struck by the bat. A fan observes that it takes 3.00 s for the ball to reach its maximum height. Find (a) The ball’s initial velocity and (b) The height it reaches.

> A model rocket is launched straight upward with an initial speed of 50.0 m/s. It accelerates with a constant upward acceleration of 2.00 m/s2 until its engines stop at an altitude of 150. m. (a) What can you say about the motion of the rocket after its e

> A package is dropped from a helicopter that is descending steadily at a speed υ0. After t seconds have elapsed, (a) What is the speed of the package in terms of υ0, g, and t? (b) What distance d is it from the helicopter in terms of g and t? (c) What are

> A tennis player tosses a tennis ball straight up and then catches it after 2.00 s at the same height as the point of release. (a) What is the acceleration of the ball while it is in flight? (b) What is the velocity of the ball when it reaches its maximum

> A small mailbag is released from a helicopter that is descending steadily at 1.50 m/s. After 2.00s (a) what is the speed of the mailbag, and (b) How far is it below the helicopter? (c) What are your answers to parts (a) and (b) if the helicopter is risin

> If you push on a heavy box that is at rest, you must exert some force to start its motion. Once the box is sliding, why does a smaller force maintain its motion?

> Traumatic brain injury such as concussion results when the head undergoes a very large acceleration. Generally, an acceleration less than 800 m/s2 lasting for any length of time will not cause injury, whereas an acceleration greater than 1000 m/s2 lastin

> An attacker at the base of a castle wall 3.65 m high throws a rock straight up with speed 7.40 m/s at a height of 1.55 m above the ground. (a) Will the rock reach the top of the wall? (b) If so, what is the rock’s speed at the top? If not, what initial s

> A certain freely falling object, released from rest, requires 1.50 s to travel the last 30.0 m before it hits the ground. (a) Find the velocity of the object when it is 30.0 m above the ground. (b) Find the total distance the object travels during the fa

> A ball is thrown directly downward with an initial speed of 8.00 m/s, from a height of 30.0 m. After what time interval does it strike the ground?

> A ball is thrown vertically upward with a speed of 25.0 m/s. (a) How high does it rise? (b) How long does it take to reach its highest point? (c) How long does the ball take to hit the ground after it reaches its highest point? (d) What is its velocity w

> A train 4.00 x 102 m long is moving on a straight track with a speed of 82.4 km/h. The engineer applies the brakes at a crossing, and later the last car passes the crossing with a speed of 16.4 km/h. Assuming constant acceleration, determine how long the

> A hockey player is standing on his skates on a frozen pond when an opposing player, moving with a uniform speed of 12 m/s, skates by with the puck. After 3.0 s, the first player makes up his mind to chase his opponent. If he accelerates uniformly at 4.0

> The kinematic equations can describe phenomena other than motion through space and time. Suppose x represents a person’s bank account balance. The units of x would be dollars ($), and velocity υ would give the rate at which the balance changes (in units

> In the Daytona 500 auto race, a Ford Thunderbird and a Mercedes Benz are moving side by side down a straightaway at 71.5 m/s. The driver of the Thunderbird realizes that she must make a pit stop, and she smoothly slows to a stop over a distance of 250 m.

> A car starts from rest and travels for t1 seconds with a uniform acceleration a1. The driver then applies the brakes, causing a uniform acceleration a2. If the brakes are applied for t2 seconds, (a) How fast is the car going just before the beginning of

> A ball is projected horizontally from the top of a building. One second later, another ball is projected horizontally from the same point with the same velocity. (a) At what point in the motion will the balls be closest to each other? (b) Will the first

> A car starts from rest and travels for 5.0 s with a uniform acceleration of +1.5 m/s2. The driver then applies the brakes, causing a uniform acceleration of -2.0 m/s2. If the brakes are applied for 3.0 s, (a) How fast is the car going at the end of the b

> A car accelerates uniformly from rest to a speed of 40.0 mi/h in 12.0 s. Find (a) The distance the car travels during this time and (b) The constant acceleration of the car.

> A train is traveling down a straight track at 20 m/s when the engineer applies the brakes, resulting in an acceleration of -1.0 m/s2 as long as the train is in motion. How far does the train move during a 40-s time interval starting at the instant the br

> A record of travel along a straight path is as follows: 1. Start from rest with a constant acceleration of 2.77 m/s2 for 15.0 s. 2. Maintain a constant velocity for the next 2.05 min. 3. Apply a constant negative acceleration of -9.47 m/s2 for 4.39 s. (a

> Speedy Sue, driving at 30.0 m/s, enters a one-lane tunnel. She then observes a slow-moving van 155 m ahead traveling at 5.00 m/s. Sue applies her brakes but can accelerate only at -2.00 m/s2 because the road is wet. Will there be a collision? State how y

> A jet plane lands with a speed of 100 m/s and can accelerate at a maximum rate of -5.00 m/s2 as it comes to rest. (a) From the instant the plane touches the runway, what is the minimum time needed before it can come to rest? (b) Can this plane land on a

> In a test run, a certain car accelerates uniformly from zero to 24.0 m/s in 2.95 s. (a) What is the magnitude of the car’s acceleration? (b) How long does it take the car to change its speed from 10.0 m/s to 20.0 m/s? (c) Will doubling the time always do

> An object moves with constant acceleration 4.00 m/s2 and over a time interval reaches a final velocity of 12.0 m/s. (a) If its original velocity is 6.00 m/s, what is its displacement during the time interval? (b) What is the distance it travels during th

> A Cessna aircraft has a liftoff speed of 120. km/h. (a) What minimum constant acceleration does the aircraft require if it is to be airborne after a takeoff run of 240. m? (b) How long does it take the aircraft to become airborne?

> A speedboat increases its speed uniformly from υi = 20.0 m/s to υf = 30.0 m/s in a distance of 2.00 x 102 m. (a) Draw a coordinate system for this situation and label the relevant quantities, including vectors. (b) For the given information, what single

> A space explorer is moving through space far from any planet or star. He notices a large rock, taken as a specimen from an alien planet, floating around the cabin of the ship. Should he push it gently, or should he kick it toward the storage compartment?

> A truck covers 40.0 m in 8.50 s while uniformly slowing down to a final velocity of 2.80 m/s. (a) Find the truck’s original speed. (b) Find its acceleration.

> In 1865 Jules Verne proposed sending men to the Moon by firing a space capsule from a 220-m-long cannon with final speed of 10.97 km/s. What would have been the unrealistically large acceleration experienced by the space travelers during their launch? (A

> An object moving with uniform acceleration has a velocity of 12.0 cm/s in the positive x - direction when its x - coordinate is 3.00 cm. If its x - coordinate 2.00 s later is -5.00 cm, what is its acceleration?

> Solve Example 2.5, “Car Chase,” by a graphical method. On the same graph, plot position versus time for the car and the trooper. From the intersection of the two curves, read the time at which the trooper overtakes the

> A steam catapult launches a jet aircraft from the aircraft carrier John C. Stennis, giving it a speed of 175 mi/h in 2.50 s. (a) Find the average acceleration of the plane. (b) Assuming the acceleration is constant, find the distance the plane moves.

> If you press a book flat against a vertical wall with your hand, in what direction is the friction force exerted by the wall on the book? (a) Downward (b) Upward (c) Out from the wall (d) Into the wall.

> The velocity vs. time graph for an object moving along a straight path is shown in Figure P2.24. (i) Find the average acceleration of the object during the time intervals (a) 0 to 5.0 s, (b) 5.0 s to 15 s, and (c) 0 to 20 s. (ii) Find the instantaneo

> A small sports car collides head-on with a massive truck. The greater impact force (in magnitude) acts on (a) The car, (b) The truck, (c) Neither, the force is the same on both. Which vehicle undergoes the greater magnitude acceleration? (d) The car, (e)

> Respond to each statement, true or false: (a) No force of gravity acts on an astronaut in an orbiting space station. (b) At three Earth radii from the center of Earth, the acceleration of gravity is one-ninth its surface value. (c) If two identical plane

> Which has greater value, a newton of gold on Earth or a newton of gold on the Moon? (a) The newton of gold on the Earth. (b) The newton of gold on the Moon. (c) The value is the same, regardless.

> Which of the following statements are true? (a) An object can move even when no force acts on it. (b) If an object isn’t moving, no external forces act on it. (c) If a single force acts on an object, the object accelerates. (d) If an object accelerates,

> For the woman being pulled forward on the toboggan in Figure 4.33, is the magnitude of the normal force exerted by the ground on the toboggan (a) Equal to the total weight of the woman plus the toboggan, (b) Greater than the total weight, (c) Less than t

> Consider the two situations shown in Figure 4.30, in which there is no acceleration. In both cases the men pull with a force of magnitude F. Is the reading on the scale in part (i) of the figure (a) Greater than, (b) Less than, or (c) Equal to the readin

> Suppose your friend is sitting on a sled and asks you to move her across a flat, horizontal field. You have a choice of (a) Pushing her from behind by applying a force downward on her shoulders at 30° below the horizontal (Fig. 4.22a) or (b) A

> A crate is sitting in the center of a flatbed truck. As the truck accelerates to the east, the crate moves with it, and doesn’t slide on the bed of the truck. In what direction is the friction force exerted by the bed of the truck on the crate? (a) To th

> As a projectile moves in its parabolic path, where are the velocity and acceleration vectors perpendicular to each other? (a) Everywhere along the projectile’s path (b) At the peak of its path (c) Nowhere along its path (d) Not enough information is give

> Suppose you are carrying a ball and running at constant velocity on level ground. You wish to throw the ball and catch it as it comes back down. Neglecting air resistance, should you (a) Throw the ball at an angle of about 45° above the horizontal and ma

> A certain car is capable of accelerating at a rate of 0.60 m/s2. How long does it take for this car to go from a speed of 55 mi/h to a speed of 60 mi/h?

> A girl on a bicycle takes 15.0 s to ride halfway around a circular track of radius 10.0 m (Figure 3.4). (a) What is the girl’s average speed? (b) What is the magnitude of her average velocity?

> Consider the following controls in an automobile: gas pedal, brake, steering wheel. The controls in this list that can cause an acceleration of the car are (a) All three controls (b) The gas pedal and the brake (c) Only the brake (d) Only the gas pedal.

> Which of the following objects can’t be accelerating? (a) An object moving with a constant speed (b) An object moving with a constant velocity or (c) An object moving along a curve.

> A woman at an airport is towing her 20.0-kg suitcase at constant speed by pulling on a strap at an angle u above the horizontal (Fig. 4.76). She pulls on the strap with a 35.0-N force, and the friction force on the suitcase is 20.0 N. (a) Draw a free-bod

> (a) What is the resultant force exerted by the two cables supporting the traffic light in Figure P4.75? (b) What is the weight of the light? Figure P4.75: