All Matches
Solution Library
Expert Answer
Textbooks
Search Textbook questions, tutors and Books
Oops, something went wrong!
Change your search query and then try again
Toggle navigation
FREE Trial
S
Books
FREE
Tutors
Study Help
Expert Questions
Accounting
General Management
Mathematics
Finance
Organizational Behaviour
Law
Physics
Operating System
Management Leadership
Sociology
Programming
Marketing
Database
Computer Network
Economics
Textbooks Solutions
Accounting
Managerial Accounting
Management Leadership
Cost Accounting
Statistics
Business Law
Corporate Finance
Finance
Economics
Auditing
Ask a Question
Search
Search
Sign In
Register
study help
physics
mechanics
Questions and Answers of
Mechanics
Discuss the nature of the work done by the equipment shown in this photo. What types of forces are involved?
The work done by a conservative force is indicated in FIGURE 8-23 for a variety of different paths connecting the points A and B. What is the work done by this force(a) On path 1(b) On path 2?
A student lifts a 1.42-kg book from her desk to a bookshelf. If the gravitational potential energy of the book-Earth system increases by 9.08 J, how high is the bookshelf above the desk?
At the local ski slope, an 82.0-kg skier rides a gondola to the top of the mountain. If the lift has a length of 2950 m and makes an angle of 13.1° with the horizontal, what is the change in the
Experiments performed on the wing of a hawkmoth (Manduca sexta) show that it deflects by a distance of x = 4.8 mm when a force of magnitude F = 3.0 mN is applied at the tip, as indicated in FIGURE
A vertical spring stores 0.962 J in spring potential energy when a 3.5-kg mass is suspended from it.(a) By what multiplicative factor does the spring potential energy change if the mass attached to
Pushing on the pump of a soap dispenser compresses a small spring. When the spring is compressed 0.50 cm, its potential energy is 0.0025 J. (a) What is the force constant of the spring? (b) What
A peacock mantis shrimp smashes its prey with a hammer-like appendage by storing energy in a spring like section of exoskeleton on its appendage. The spring has a force constant of 5.9 × 104 N/m.(a)
The work required to stretch a certain spring from an elongation of 4.00 cm to an elongation of 5.00 cm is 30.5 J.(a) Is the work required to increase the elongation of the spring from 5.00 cm to
A 0.33-kg pendulum bob is attached to a string 1.2 m long. What is the change in the gravitational potential energy of the system as the bob swings from point A to point B in FIGURE 8-29?
(a) You throw a ball upward and let it fall to the ground. Your friend drops an identical ball straight down to the ground from the same height. Is the change in kinetic energy of your ball greater
When a ball of mass m is dropped from rest from a height h, its kinetic energy just before landing is K. Now, suppose a second ball of mass 4m is dropped from rest from a height h/4. (a) Just before
Calculate the work done by gravity as a 3.2-kg object is moved from point A to point B in FIGURE 8-24 along paths 1, 2, and 3.
For an object moving along the x axis, the potential energy of the frictionless system is shown in FIGURE 8-30. Suppose the object is released from rest at the point A. Rank the other points in the
At an amusement park, a swimmer uses a water slide to enter the main pool. If the swimmer starts at rest, slides without friction, and descends through a vertical height of 2.31 m, what is her speed
A player passes a 0.600-kg basketball downcourt for a fast break. The ball leaves the player's hands with a speed of 8.30 m/s and slows down to 7.10 m/s at its highest point.(a) Ignoring air
A skateboarder at a skate park rides along the path shown in FIGURE 8-31. If the speed of the skateboarder at point A is v = 1.4 m/s, what is her speed at point B? Assume that friction is negligible.
Three balls are thrown upward with the same initial speed v0, but at different angles relative to the horizontal, as shown in FIGURE 8-32. Ignoring air resistance, indicate which of the following
A 0.21-kg apple falls from a tree to the ground, 4.0 m below. Ignoring air resistance, determine the apple's kinetic energy, K, the gravitational potential energy of the system, U, and the total
A 2.9-kg block slides with a speed of 2.1 m/s on a frictionless horizontal surface until it encounters a spring.(a) If the block compresses the spring 5.6 cm before coming to rest, what is the force
A 0.26-kg rock is thrown vertically upward from the top of a cliff that is 32 m high. When it hits the ground at the base of the cliff, the rock has a speed of 29 m/s. Assuming that air resistance
A 1.40-kg block slides with a speed of 0.950 m/s on a frictionless horizontal surface until it encounters a spring with a force constant of 734 N/m. The block comes to rest after compressing the
A 5.76-kg rock is dropped and allowed to fall freely. Find the initial kinetic energy, the final kinetic energy, and the change in kinetic energy for(a) The first 2.00 m of fall(b) The second 2.00 m
Calculate the work done by friction as a 3.7-kg box is slid along a floor from point A to point B in FIGURE 8-25 along paths 1, 2, and 3. Assume that the coefficient of kinetic friction between the
Suppose the pendulum bob in Figure 8-29 has a mass of 0.33 kg and is moving to the right at point B with a speed of 2.4 m/s. Air resistance is negligible.(a) What is the change in the system's
The two masses in the Atwood's machine shown in FIGURE 8-33 are initially at rest at the same height. After they are released, the large mass, m2, falls through a height h and hits the floor, and the
In the previous problem, suppose the masses have an initial speed of 0.20 m/s, and that m2 is moving upward. How high does m2 rise above its initial position before momentarily coming to rest, given
On reentry, the Space Shuttle's protective heat tiles became extremely hot. (a) Was the mechanical energy of the Shuttle-Earth system when the Shuttle landed greater than, less than, or the same as
Catching a wave, a 77-kg surfer starts with a speed of 1.3 m/s, drops through a height of 1.65 m, and ends with a speed of 8.2 m/s. How much nonconservative work was done on the surfer?
At a playground, a 19-kg child plays on a slide that drops through a height of 2.3 m. The child starts at rest at the top of the slide. On the way down, the slide does a nonconservative work of -361
Starting at rest at the edge of a swimming pool, a 72.0-kg athlete swims along the surface of the water and reaches a speed of 1.20 m/s by doing the work Wnc1 = + 161 J. Find the nonconservative
A 22,000-kg airplane lands with a speed of 64 m/s on a stationary aircraft carrier deck that is 115 m long. Find the work done by nonconservative forces in stopping the plane.
A 78-kg skateboarder grinds down a hubba ledge that is 2.5 m long and inclined at 19° below the horizontal. Kinetic friction dissipates half of her initial potential energy to thermal and sound
You ride your bicycle down a hill, maintaining a constant speed the entire time. (a) As you ride, does the gravitational potential energy of the you-bike-Earth system increase, decrease, or stay the
A 2.8-kg block is attached to a spring with a force constant of 375 N/m, as shown in FIGURE 8-26.(a) Find the work done by the spring on the block as the block moves from A to B along paths 1 and
A 111-kg seal at an amusement park slides from rest down a ramp into the pool below. The top of the ramp is 1.75 m higher than the surface of the water, and the ramp is inclined at an angle of 26.5°
A 1.9-kg rock is released from rest at the surface of a pond 1.8 m deep. As the rock falls, a constant upward force of 4.6 N is exerted on it by water resistance. Calculate the nonconservative work,
A 1250-kg car drives up a hill that is 16.2 m high. During the drive, two nonconservative forces do work on the car: (i) The force of friction, (ii) The force generated by the car's engine. The work
The Outlaw Run roller coaster in Branson, Missouri, features a track that is inclined at 81° below the horizontal and that spans a 49.4-m (162 ft) change in height.(a) If the coefficient of friction
A 1.80-kg block slides on a rough horizontal surface. The block hits a spring with a speed of 2.00 m/s and compresses it a distance of 11.0 cm before coming to rest. If the coefficient of kinetic
FIGURE 8-34 shows a potential energy curve as a function of x. In qualitative terms, describe the subsequent motion of an object that starts at rest at point A.
An object moves along the x axis, subject to the potential energy shown in Figure 8-34. The object has a mass of 1.1 kg and starts at rest at point A.(a) What is the object's speed at point B?(b) At
A 1.34-kg object moves along the x axis, subject to the potential energy shown in Figure 8-34. If the object's speed at point C is 1.25 m/s, what are the approximate locations of its turning points?
The potential energy of a particle moving along the x axis is shown in Figure 8-34. When the particle is at x = 1.0 m it has 3.6 J of kinetic energy. Give approximate answers to the following
A block of mass m = 0.88 kg is connected to a spring of force constant k = 845 N / m on a smooth, horizontal surface.(a) Plot the potential energy of the spring from x = -5.00 cm to x = 5.00 cm.(b)
(a) Calculate the work done by gravity as a 5.2-kg object is moved from A to B in FIGURE 8-27 along paths 1 and 2.(b) How do your results depend on the mass of the block? Specifically, if you
A ball of mass m = 0.75 kg is thrown straight upward with an initial speed of 8.9 m/s.(a) Plot the gravitational potential energy of the ball from its launch height, y = 0, to the height y = 5.0 m.
FIGURE 8-35 depicts the potential energy of a 350-kg pallet that slides from rest down a frictionless roller conveyer ramp, then moves across a frictionless horizontal conveyer, and finally
Figure 8-35 depicts the potential energy of a 655-kg pallet that slides from rest down a frictionless roller conveyer ramp, then moves across a frictionless horizontal conveyer, and finally
You and a friend both solve a problem involving a skier going down a slope. When comparing solutions, you notice that your choice for the y = 0 level is different than the y = 0 level chosen by your
A particle moves under the influence of a conservative force. At point A the particle has a kinetic energy of 12 J; at point B the particle is momentarily at rest, and the potential energy of the
A sled slides without friction down a small, ice-covered hill. On its first run down the hill, the sled starts from rest at the top of the hill and its speed at the bottom is 7.50 m/s. On a second
A 74-kg skier encounters a dip in the snow's surface that has a circular cross section with a radius of curvature of 12 m. If the skier's speed at point A in FIGURE 8-36 is 7.1 m/s, what is the
The soles of a popular make of running shoe have a force constant of 2.0 × 105 N / m. Treat the soles as ideal springs for the following questions. (a) If a 62-kg person stands in a pair of these
The force required to flex a nasal strip and apply it to the nose is 0.25 N; the energy stored in the strip when flexed is 0.0022 J. Assume the strip to be an ideal spring for the following
The water slide shown in FIGURE 8-37 ends at a height of 1.50 m above the pool. If the person starts from rest at point A and lands in the water at point B, what is the height h of the water slide?
In the system shown in Figure 8-26, suppose the block has a mass of 2.7 kg, the spring has a force constant of 480 N/m, and the coefficient of kinetic friction between the block and the floor is
A skateboarder starts at point A in FIGURE 8-38 and rises to a height of 2.64 m above the top of the ramp at point B. What was the skateboarder's initial speed at point A?
NASA's Skylab, the largest spacecraft ever to fall back to the Earth, reentered the Earth's atmosphere on July 11, 1979, and broke into a myriad of pieces. One of the largest fragments was a 1770-kg,
Several studies indicate that the elastic properties of tendons can change in response to exercise. In one study, guinea fowl were divided into a group that ran for 30 minutes a day on a treadmill,
In the Atwood's machine of Problem 31, the mass m2 remains at rest once it hits the floor, but the mass m1 continues moving upward. How much higher does m1 go after m2 has landed? Give your answer
A 6.60-kg block slides with an initial speed of 2.24 m/s up a ramp inclined at an angle of 18.4° with the horizontal. The coefficient of kinetic friction between the block and the ramp is 0.44. Use
Jeff of the Jungle swings on a 7.6-m vine that initially makes an angle of 37° with the vertical. If Jeff starts at rest and has a mass of 78 kg, what is the tension in the vine at the lowest point
A 1.9-kg block slides down a frictionless ramp, as shown in FIGURE 8-40. The top of the ramp is 1.5 m above the ground; the bottom of the ramp is 0.25 m above the ground. The block leaves the ramp
Suppose the ramp in Figure 8-40 is not frictionless. Find the distance d for the case in which friction on the ramp does - 9.7 J of work on the block before it becomes airborne.
A running track at Harvard University uses a surface with a force constant of 2.5 × 105 N / m. This surface is compressed slightly every time a runner's foot lands on it. The force exerted by the
The resilin in the body of a flea has a force constant of about 24 N/m, and when the flea cocks its jumping legs, the resilin associated with each leg is compressed by approximately 0.12 mm. Given
(a) Ball 1 is thrown to the ground with an initial downward speed; ball 2 is dropped to the ground from rest. Assuming the balls have the same mass and are released from the same height, is the
A ball of mass m is attached to a string of length L and released from rest at the point A in FIGURE 8-41.(a) Show that the tension in the string when the ball reaches point B is 3mg, independent of
An ice cube is placed on top of an overturned spherical bowl of radius r, as indicated in FIGURE 8-42. If the ice cube slides downward from rest at the top of the bowl, at what angle θ does it
The two blocks shown in FIGURE 8-43 are moving with an initial speed v.(a) If the system is frictionless, find the distance d the blocks travel before coming to rest. (Let U = 0 correspond to the
(a) A block of mass m slides from rest on a frictionless loop-the-loop track, as shown in FIGURE 8-44. What is the minimum release height, h, required for the block to maintain contact with the track
FIGURE 8-45 shows a 1.75-kg block at rest on a ramp of height h. When the block is released, it slides without friction to the bottom of the ramp, and then continues across a surface that is
In FIGURE 8-46 a 1.2-kg block is held at rest against a spring with a force constant k = 730 N/m. Initially, the spring is compressed a distance d. When the block is released, it slides across a
Treating the model wing as an ideal spring, what is the force constant of the hind wing when a force is applied to its tip?A. 94 N/mB. 130 N/mC. 290 N/mD. 330 N/m
What is the force constant of the hind wing when a force is applied at two-thirds the distance from the base of the wing to the tip?A. 94 N/mB. 130 N/mC. 290 N/mD. 330 N/m
Which of the wings is "stiffer"?A. The hindwingB. The forewingC. Depends on where the force is appliedD. They are equally "stiff"
How much energy is stored in the forewing when a force at the tip deflects it by 3.5 mm?A. 0.766 mJB. 49.0 mJC. 0.219 JD. 1.70 kJ
A mass is attached to the bottom of a vertical spring. This causes the spring to stretch and the mass to move downward.(a) Does the potential energy of the spring increase, decrease, or stay the same
Consider a spring with a force constant of 955 N/m.(a) Suppose the mass of the block is 1.70 kg, but its initial speed can be varied. What initial speed is required to give a maximum spring
Suppose the block is released from rest with the spring compressed 5.00 cm. The mass of the block is 1.70 kg and the force constant of the spring is 955 N/m.(a) What is the speed of the block when
Suppose we would like the landing speed of block 2 to be increased to 1.50 m/s.(a) Should the coefficient of kinetic friction between block 1 and the tabletop be increased or decreased?(b) Find the
Find the gravitational potential energy of an 88-kg person standing atop Mt. Everest at an altitude of 8848 m. Use sea level as the location for y = 0.
An hourglass is turned over, and the sand is allowed to pour from the upper half of the glass to the lower half. If the hourglass is resting on a scale, and the total mass of the hourglass and sand
A tall, slender drinking glass with a thin base is initially empty. (a) Where is the center of mass of the glass? (b) Suppose the glass is now filled slowly with water until it is completely full.
In the "Fosbury flop" method of high jumping, named for the track and field star Dick Fosbury, an athlete's center of mass may pass under the bar while the athlete's body passes over the bar. Explain
A system of particles is known to have zero momentum. Does it follow that the kinetic energy of the system is also zero? Explain.
Crash statistics show that it is safer to be riding in a heavy car in an accident than in a light car. Explain in terms of physical principles.
An object at rest on a frictionless surface is struck by a second object. Is it possible for both objects to be at rest after the collision? Explain.
What is the mass of a mallard duck whose speed is 8.9 m/s and whose momentum has a magnitude of 11 kg ∙ m/s?
A net force of 200 N acts on a 100-kg boulder, and a force of the same magnitude acts on a 100-g pebble. (a) Is the change of the boulder's momentum in one second greater than, less than, or equal to
Referring to the previous question, (a) Is the change in the boulder's speed in one second greater than, less than, or equal to the change in speed of the pebble in the same time period? (b) Choose
Two identical cars, each traveling at 16 m/s, slam into a concrete wall and come to rest. In car A the air bag does not deploy and the driver hits the steering wheel; in car B the driver contacts the
Force A has a magnitude F and acts for the time Δt, force B has a magnitude 2F and acts for the time Δt/3, force C has a magnitude 5F and acts for the time Δt/10, and force D has a magnitude 10F
Find the magnitude of the impulse delivered to a soccer ball when a player kicks it with a force of 1250 N. Assume that the player's foot is in contact with the ball for 5.95 × 10-3 s.
A 0.45-kg croquet ball is initially at rest on the grass. When the ball is struck by a mallet, the average force exerted on it is 270 N. If the ball's speed after being struck is 5.4 m/s, for what
When spiking a volleyball, a player changes the velocity of the ball from 4.2 m/s to -24 m/s along a certain direction. If the impulse delivered to the ball by the player is -9.3 kg ∙ m/s, what is
A force platform measures the horizontal force exerted on a person's foot by the ground. In FIGURE 9-26 we see force-versus-time data taken by a force platform for a person who starts jogging at time
If a driver makes contact with a steering wheel during a 35-mph crash, she comes to rest in about Δt = 15 ms. If, during an identical crash, the driver makes contact with an air bag, she comes to
To make a bounce pass, a player throws a 0.60-kg basketball toward the floor. The ball hits the floor with a speed of 5.4 m/s at an angle of 65° to the vertical. If the ball rebounds with the same
Showing 19600 - 19700
of 21805
First
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
Last