Questions and Answers of College Physics A Strategic Approach 2nd

A somewhat idealized graph of the speed of the blood in the ascending aorta during one beat of the heart appears as in Figure P2.18.a. Approximately how far, in cm, does the blood move during one
The following options describe the motion of four cars A-D. Which car has the largest acceleration?A. Goes from 0 m/s to 10 m/s in 5.0 s B. Goes from 0 m/s to 5.0 m/s in 2.0 s C. Goes from 0 m/s to
A car starts from xi = 10 m at ti = 0 s and moves with the velocity graph shown in Figure P2.19. a. What is the object's position at t = 2 s, 3 s, and 4 s?b. Does this car ever change direction on?
A car is traveling at vx 20 m/s. The driver applies the brakes, and the car slows with ax = -4.0 m/s2. What is the stopping distance? A. 5.0 m B. 25 m C. 40 m D. 50 m
Figure P2.20 shows a graph of actual position-versus-time data for a particular type of drag racer known as a "funny car." Figure P2.20a. Estimate the car's velocity at 2.0 s. b. Estimate the car's
Velocity-versus-time graphs for three drag racers are shown in Figure Q2.20. At t =5.0 s, which car has traveled the furthest?A. Andy B. Betty C. Carl D. All have traveled the same distance. v,
Ball 1 is thrown straight up in the air and, at the same instant, ball 2 is released from rest and allowed to fall. Which velocity graph in Figure Q2.22 best represents the motion of the two
For each motion diagram shown earlier in Figure P2.2, determine the sign (positive or negative) of the acceleration.Figure P2.2, (a) 0 X (b) 0 (c)
Figure P2.18 showed data for the speed of blood in the aorta. Determine the magnitude of the acceleration for both phases, speeding up and slowing down. v (m/s) 1.0 0.5- FIGURE P2.18 0 0.20 0.40 0.60
A car can go from 0 to 60 mph in 7.0 s. Assuming that it could maintain the same acceleration at higher speeds, how long would it take the car to go from 0 to 120 mph? A. 10 s B. 14 s C. 21 s D.
Figure P2.25 is a somewhat simplified velocity graph for Olympic sprinter Carl Lewis starting a 100 m dash. Estimate his acceleration during each of the intervals A, B, and C.Figure P2.25 v,
A car can go from 0 to 60 mph in 12 s. A second car is capable of twice the acceleration of the first car. Assuming that it could maintain the same acceleration at higher speeds, how much time will
A Thomson's gazelle can reach a speed of 13 m/s in 3.0 s. A lion can reach a speed of 9.5 m/s in 1.0 s. A trout can reach a speed of 2.8 m/s in 0.12 s. Which animal has the largest acceleration?
When striking, the pike, a predatory fish, can accelerate from rest to a speed of 4.0 m/s in 0.11 s.a. What is the acceleration of the pike during this strike? b. How far does the pike move during
Light-rail passenger trains that provide transportation within and between cities are capable of modest accelerations. The magnitude of the maximum acceleration is typically 1.3 m/s2, but the driver
Figure P2.32 shows a velocity-versus-time graph for a particle moving along the x-axis. At t = 0 s, assume that x = 0 m.a. What are the particle's position, velocity, and acceleration at t = 1.0
A small propeller airplane can comfortably achieve a high enough speed to take off on a runway that is 1/4 mile long. A large, fully loaded passenger jet has about the same acceleration from rest,
A driver has a reaction time of 0.50 s, and the maximum deceleration of her car is 6.0 m/s2. She is driving at 20 m/s when suddenly she sees an obstacle in the road 50 m in front of her. Can she stop
Chameleons catch insects with their tongues, which they can rapidly extend to great lengths. In a typical strike, the chameleon's tongue accelerates at a remarkable 250 m/s2 for 20 ms, then travels
A light-rail train going from one station to the next on a straight section of track accelerates from rest at 1.1 m/s2 for 20 s. It then proceeds at constant speed for 1100 m before slowing down at
A simple model for a person running the 100 m dash is to assume the sprinter runs with constant acceleration until reaching top speed, then maintains that speed through the finish line. If a sprinter
Ball bearings can be made by letting spherical drops of molten metal fall inside a tall tower-called a shot tower-and solidify as they fall. a. If a bearing needs 4.0 s to solidify enough for
A student at the top of a building of height h throws ball A straight upward with speed vo and throws ball B straight down- ward with the same initial speed. a. Compare the balls' accelerations,
Excellent human jumpers can leap straight up to a height of 110 cm off the ground. To reach this height, with what speed would a person need to leave the ground?
A football is kicked straight up into the air; it hits the ground 5.2 s later. a. What was the greatest height reached by the ball? Assume it is kicked from ground level. b. With what speed did it
In an action movie, the villain is rescued from the ocean by grabbing onto the ladder hanging from a helicopter. He is so intent on gripping the ladder that he lets go of his briefcase of counterfeit
A rock climber stands on top of a 50-m-high cliff overhanging a pool of water. He throws two stones vertically downward 1.0 s apart and observes that they cause a single splash. The initial speed of
A truck driver has a shipment of apples to deliver to a destination 440 miles away. The trip usually takes him 8 hours. Today he finds himself daydreaming and realizes 120 miles into his trip that he
Does a real automobile have constant acceleration? Measured data for a Porsche 944 Turbo at maximum acceleration are as shown in the table. a. Convert the velocities to m/s, then make a graph of
When you sneeze, the air in your lungs accelerates from rest to approximately 150 km/h in about 0.50 seconds. a. What is the acceleration of the air in m/s2? b. What is this acceleration, in units
People hoping to travel to other worlds are faced with huge challenges. One of the biggest is the time required for a journey. The nearest star is 4.1 x 1016 m away. Suppose you had a spacecraft that
You are driving to the grocery store at 20 m/s. You are 110 m from an intersection when the traffic light turns red. Assume that your reaction time is 0.70 s and that your car brakes with constant
When you blink your eye, the upper lid goes from rest with your eye open to completely covering your eye in a time of 0.024 s. a. Estimate the distance that the top lid of your eye moves during a
A bush baby, an African primate, is capable of leaping vertically to the remarkable height of 2.3 m. To jump this high, the bush baby accelerates over a distance of 0.16 m while rapidly extending its
When jumping, a flea reaches a takeoff speed of 1.0 m/s over a distance of 0.50 mm.a. What is the flea's acceleration during the jump phase? b. How long does the acceleration phase last? c. If the
Certain insects can achieve seemingly impossible accelerations while jumping. The click beetle accelerates at an astonishing 400g over a distance of 0.60 cm as it rapidly bends its thorax, making the
Divers compete by diving into a 3.0-m-deep pool from a platform 10 m above the water. What is the magnitude of the minimum acceleration in the water needed to keep a diver from hitting the bottom of
A juggler throws a ball straight up into the air with a speed of 10 m/s. With what speed would she need to throw a second ball half a second later, starting from the same position as the first. in
A car starts from rest at a stop sign. It accelerates at 2.0 m/s2 for 6.0 seconds, coasts for 2.0 s, and then slows down at a rate of 1.5 m/s2 for the next stop sign. How far apart are the stop signs?
Heather and Jerry are standing on a bridge 50 m above a river. Heather throws a rock straight down with a speed of 20 m/s. Jerry, at exactly the same instant of time, throws a rock straight up with
A piano has been pushed to the top of the ramp at the back of a moving van. The workers think it is safe, but as they walk away, it begins to roll down the ramp. If the back of the truck is 1.0 m
A ball is fired from a cannon at point 1 and follows the trajectory shown in Figure Q3.21. Air resistance may be neglected. Five possible vectors are also shown in the figure; the letter E represents
Starting from rest, several toy cars roll down ramps of differing lengths and angles. Rank them according to their speed at the bottom of the ramp, from slowest to fastest. Car A goes down a 10 m
A ball thrown at an initial angle of 37.0° and initial velocity of 23.0 m/s reaches a maximum height h, as shown in Figure Q3.22. With what initial speed must a ball be thrown straight up to reach
A cannon, elevated at 40° is fired at a wall 300 m away on level ground, as shown in Figure Q3.23. The initial speed of the cannonball is 89 m/s.a. How long does it take for the ball to hit the
A car drives horizontally off a 73-m-high cliff at a speed of 27 m/s. Ignore air resistance. a. How long will it take the car to hit the ground? A. 2.0 s B. 3.2 s C. 3.9 s D. 4.9 s E. 5.0 s b.
A plane has an airspeed of 200 mph. The pilot wishes to reach a destination 600 mi due east, but a wind is blowing at 50 mph in the direction 30° north of east. a. In what direction must the pilot
A 1000 kg car traveling at a speed of 40 m/s skids to a halt on wet concrete where μk = 0.60. How long are the skid marks?
Eric has a mass of 60 kg. He is standing on a scale in an elevator that is accelerating downward at 1.7 m/s2. What is the approximate reading on the scale?A. ON B. 400 N C. 500 N D. 600 N
The two blocks in Figure Q5.28 are at rest on frictionless surfaces. What must be the mass of the right block in order that the two blocks remain stationary?A. 4.9 kg B. 6.1 kg C. 7.9 kgD. 9.8
A 5.0-m-diameter merry-go-round is turning with a 4.0 s period. What is the speed of a child on the rim?
A 50 g ball of clay traveling at speed vi hits and sticks to a 1.0 kg block sitting at rest on a frictionless surface. a. What is the speed of the block after the collision? b. Show that the
Jake hits a ball at a 600 angle from the horizontal. It is caught by Jim. Draw a motion diagram of the ball that shows velocity vectors rather than displacement vectors.This example is typical of how
A man rides a bike along a straight road for 5 min, then has a flat tire. He stops for 5 min to repair the flat, but then realizes he cannot fix it. He continues his journey by walking the rest of
A jogger running east at a steady pace suddenly develops a cramp. He is lucky: A westbound bus is sitting at a bus stop just ahead. He gets on the bus and enjoys a quick ride home. Use the particle
A ball is dropped from the roof of a tall building and students in a physics class are as ked to sketch a motion diagram for this situation. A student submits the diagram shown in Figure Q1.4. Is the
Figure P1.4 shows Sue between her home and the cinema. What is Sue's position x if.a. Her home is the origin? b. The cinema is the origin? FIGURE P1.4 Home 2 mi Sue 3 mi Cinema
Write a sentence or two describing the difference between position and displacement. Give one example of each.
Keira starts at position x = 23 m along a coordinate axis. She then undergoes a displacement of -45 m. What is her final position?
Give an example of a trip you might take in your car for which the distance traveled as measured on your car's odometer is not equal to the displacement between your initial and final positions.
A car travels along a straight east-west road. A coordinate system is established on the road, with x increasing to the east. The car ends up 14 mi west of the intersection with Mulberry Road. If its
Write a sentence or two describing the difference between speed and velocity. Give one example of each.
Foraging bees often move in straight lines away from and toward their hives. Suppose a bee starts at its hive and flies 500 m due east, then flies 400 m west, then 700 m east. How far is the bee from
The motion of a skateboard along a horizontal axis is observed for 5 s. The initial position of the skateboard is negative with respect to a chosen origin, and its velocity throughout the 5 s is also
A security guard walks 110 m in one trip around the perimeter of the building. It takes him 240 s to make this trip. What is his speed?
Can the velocity of an object be positive during a time interval in which its position is always negative? Can its velocity be positive during a time interval in which its displacement is negative?
List the following items in order of decreasing speed, from greatest to least:(i) A wind-up toy car that moves 0.15 m in 2.5 s. (ii) A soccer ball that rolls 2.3 m in 0.55 s. (iii) A bicycle that
Two Friends watch a jogger complete a 400 m lap around the track in 100 s. One of the friends states, "The jogger's velocity was 4 m/s during this lap." The second friend objects, saying, "No, the
Figure P1.10 shows the motion diagram for a horse galloping in one direction along a straight path. Not every dot is labeled, but the dots are at equally spaced instants of time. What is the horse's
It takes Harry 35 s to walk from x = -12 m to x = -47 m. What is his velocity?
A dog trots from x = -12 m to x = 3 m in 10 s. What is its velocity?
A child is sledding on a smooth, level patch of snow. She encounters a rocky patch and slows to a stop. Draw a motion diagram, using the particle model, showing her velocity vectors.
A ball rolling along a straight line with velocity 0.35 m/s goes from x = 2.1 m to x = 7.3 m. How much time does this take?
A skydiver jumps out of an airplane. Her speed steadily increases until she deploys her parachute, at which point her speed quickly decreases. She subsequently falls to earth at a constant rate,
Convert the following to SI units: a. 9.12 μs b. 3.42 km c. 44 cm/ms d. 80 km/hour
A car is driving north at a steady speed. It makes a gradual 90° left turn without losing speed, then continues driving to the west. Draw a motion diagram, using the particle model, showing the
Convert the following to SI units: a. 1.0 hour b. 1.0 day c. 1.0 year.
A toy car rolls down a ramp, then across a smooth, horizontal floor. Draw a motion diagram, using the particle model. showing the car's velocity vectors.
List the following three speeds in order, from smallest to largest: 1 mm per μs, 1 km per ks, 1 cm per ms.
Estimate the average speed with which you go from home to campus (or another trip you commonly make) via whatever mode of transportation you use most commonly. Give your answer in both mph and m/s.
Estimate the number of times you sneezed during the past year. Describe how you arrived at this estimate.
How many significant figures does each of the following numbers have?a. 6.21 b. 62.1 c. 0.620 d. 0.062
How many significant figures does each of the following numbers have? a. 0.621 b. 0.006200 c. 1.0621d. 6.21 x 103
A student walks 1.0 mi west and then 1.0 mi north. Afterward, how far is she from her starting point? A. 1.0 mi C. 1.6 mi B. 1.4 mi D. 2.0 mi
What is the minimum down-ward force on the box in Figure P5.30 that will keep it from slipping? The coefficients of static and kinetic friction between the box and the floor are 0.35 and 0.25,
A football player at practice pushes a 60 kg blocking sled across the field at a constant speed. The coefficient of kinetic friction between the grass and the sled is 0.30. How much force must he
Two football players are pushing a 60 kg blocking sled across the field at a constant speed of 2.0 m/s. The coefficient of kinetic friction between the grass and the sled is 0.30. Once they stop
Land Rover ads used to claim that their vehicles could climb a slope of 45°. For this to be possible, what must be the mini- mum coefficient of static friction between the vehicle's tires and the
A 22-cm-diameter bowling ball has a terminal speed of 77 m/s. What is the ball's mass?
A truck is traveling at 30 m/s on a slippery road. The driver slams on the brakes and the truck starts to skid. If the coefficient of kinetic friction between the tires and the road is 0.20, how far
Each of 100 identical blocks sitting on a frictionless surface is connected to the next block by a massless string. The first block is pulled with a force of 100 N.a. What is the tension in the
Figure P5.44 shows the net force acting on a 2.0 kg object as it moves along the x-axis. The object is at rest at the origin at t=0 s. What are its acceleration and velocity at t = 6.0 s? F,
Dana has a sports medal suspended by a long ribbon from her rearview mirror. As she accelerates onto the highway, she notices that the medal is hanging at an angle of 10° from the vertical. a. Does
A 23 kg child goes down a straight slide inclined 38 above horizontal. The child is acted on by his weight, the normal force from the slide, kinetic friction, and a horizontal rope exerting a 30 N
You've always wondered about the acceleration of the elevators in the 101-story-tall Empire State Building. One day, while visiting New York, you take your bathroom scales into the elevator and stand
Josh starts his sled at the top of a 3.0-m-high hill that has a constant slope of 25°. After reaching the bottom, he slides across a horizontal patch of snow. The hill is frictionless, but the
A wood block, after being given a starting push, slides down a wood ramp at a constant speed. What is the angle of the ramp above horizontal?
A 77 kg sprinter is running the 100 m dash. At one instant, early in the race, his acceleration is 4.7 m/s2. a. What total force does the track surface exert on the sprinter? Assume his acceleration
Sam, whose mass is 75 kg, takes off across level snow on his jet-powered skis. The skis have a thrust of 200 N and a coefficient of kinetic friction on snow of 0.10. Unfortunately, the skis run out
Two blocks are at rest on a frictionless incline, as shown in Figure P5.65. What are the tensions in the two strings? 5.0 kg 20⁰ FIGURE P5.65 3.0 kg 2

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