2.99 See Answer

Question: What tool enabled scientists to create hundreds


What tool enabled scientists to create hundreds of different hadrons in the latter half of the twentieth century?


> In the “executive toy,” two balls are pulled back and then released. After the collision, two balls move away on the opposite side. Why do we never see three balls move away following this action, although with a lower

> Two coherent sound waves have intensities of 0.040 W/m2 and 0.090 W/m2 where you are listening. (a) If the waves interfere constructively, what is the intensity that you hear? (b) What if they interfere destructively? (c) If they were incoherent, what

> In an egg toss, two people try to toss a raw egg back and forth without breaking it as they move farther and farther apart. Discuss a strategy in terms of impulse and momentum for catching the egg without breaking it.

> The momentum of a system can only be changed by an external force. What is the external force that changes the momentum of a bicycle (with its rider) as it speeds up, slows down, or changes direction? Is it true that changes in the bicycle's kinetic ener

> A top fuel drag racer with a mass of 500.0 kg completes a quarter- mile (402 m) drag race in a time of 4.2 s starting from rest. The car’s final speed is 125 m/s. What is the engine’s average power output? Ignore friction and air resistance.

> A woman is 1.60 m tall. When standing straight, is her CM necessarily 0.80 m above the floor? Explain.

> Two solenoids, of N1 and N2 turns respectively, are wound on the same form. They have the same length â„“ and radius r. (a) If an ac current flows in solenoid 1 (N1 turns), write an expression for the total flux through solenoid 2 as a f

> Two objects with different masses have the same kinetic energy. Which has the larger magnitude of momentum?

> An airplane has a velocity relative to the ground of 210 m/s toward the east. The pilot measures his airspeed (the speed of the plane relative to the air) to be 160 m/s. What is the minimum wind velocity possible?

> You are trapped on the second floor of a burning building. The stairway is impassable, but there is a balcony outside your window. Describe what might happen in the following situations. (a) You jump from the second-story balcony to the pavement below,

> (a) Find the electric flux through each side of a cube of edge length a in a uniform electric field of magnitude E. The field direction is perpendicular to two of the faces. (b) What is the total flux through the cube?

> (a) Calculate the net electric force acting on the dipole. (b) Show that the magnitude of the torque on the dipole is τ = qEd sin θ. (c) Calculate the torque acting on the dipole for θ = 0, 36.9°, and 90.0°.

> A cheetah can accelerate from rest to 24 m/s in 2.0 s. Assuming the acceleration is constant over the time interval, (a) what is the magnitude of the acceleration of the cheetah? (b) What is the distance traveled by the cheetah in these 2.0 s? (c) A r

> A bicycle rider notices that he is approaching a steep hill. Explain, in terms of energy, why the bicyclist pedals hard to gain as much speed as possible on level road before reaching the hill.

> A gymnast is swinging in a vertical circle about a crossbar. In terms of energy conservation, explain why the speed of the gymnast’s body is slowest at the top of the circle and fastest at the bottom.

> When a ball is dropped to the floor from a height h, it strikes the ground and briefly undergoes a change of shape before rebounding to a maximum height less than h. Explain why it does not return to the same height h.

> A roller coaster car (mass = 988 kg including passengers) is about to roll down a track. The diameter of the circular loop is 20.0 m and the car starts out from rest 40.0 m above the lowest point of the track. Ignore friction and air resistance. (a) At

> A green laser has a wavelength of 532 nm. A grating and a lens are used to split the beam into three parallel beams spaced 1.85 cm apart. (a) What range of slit spacings can the grating have to produce three and only three beams? (b) If the slit spacing

> The field between the plates of a parallel plate capacitor, E = Q/(ϵ0A), is due to the superposition of equal contributions from the charges on the two plates. Therefore, each plate exerts an electric force on the other. (a) Find the magnitude of this f

> In the design of a roller coaster, is it possible for any hill of the ride to be higher than the first one? If so, how?

> Can static friction do work? If so, give an example. [Hint: Static friction acts to prevent relative motion along the contact surface.]

> A car is driving directly north on the freeway at a speed of 110 km/h, and a truck is leaving the freeway driving 85 km/h in a direction that is 35° west of north. What is the velocity of the truck relative to the car?

> The period of oscillation of an object in an ideal spring-and-mass system is 0.50 s and the amplitude is 5.0 cm. What is the speed at the equilibrium point?

> A copper washer is to be fit in place over a steel bolt. Both pieces of metal are at 20.0°C. If the diameter of the bolt is 1.0000 cm and the inner diameter of the washer is 0.9980 cm, to what temperature must the washer be raised so it will fit over the

> A mango falls to the ground. During the fall, does Earth’s gravitational field do positive or negative work Wm on the mango? Does the mango’s gravitational field do positive or negative work WE on Earth? Compare the signs and the magnitudes of Wm and WE.

> Why do roads leading to the top of a mountain have switchbacks that wind back and forth? [Hint: Think of the road as an inclined plane.]

> An infinitely long conducting cylinder sits near an infinite conducting sheet (side view in the diagram). The cylinder and sheet have equal and opposite charges; the cylinder is positive. (a) Sketch some electric field lines. (b) Sketch some equipotent

> You are standing on a balcony overlooking the beach. You throw a ball straight up into the air with speed vi and throw an identical ball straight down with speed vi. Ignoring air resistance, how do the speeds of the balls compare just before they hit the

> Why might an elevator cable break during acceleration when lifting a lighter load than it normally supports at rest or at constant velocity?

> If air resistance is ignored, what force(s) act on an object in free fall?

> An ideal transformer takes an ac voltage of amplitude 170 V as its input and supplies a 7.8 V amplitude to a circuit that converts it to dc. The primary has 300 turns. (a) How many turns does the secondary have? (b) When the circuit uses a power of 5.0

> If the trajectory is parabolic in one reference frame, is it always, never, or sometimes parabolic in another reference frame that moves at constant velocity with respect to the first reference frame? If the trajectory can be other than parabolic, what e

> What is the acceleration of an object thrown straight up into the air at the highest point of its motion? Does the answer depend on whether air resistance is negligible or not? Explain.

> Is it possible for two identical projectiles with identical initial speeds, but with two different angles of elevation, to land in the same spot? Explain. Ignore air resistance and sketch the trajectories.

> A large parallel plate capacitor with air between the plates has plate separation 1.00 cm and plate area 314 cm2. The capacitor is connected to a 20.0 V battery and then disconnected. How much work is done on the capacitor as the plate separation is incr

> A Nile cruise ship takes 20.8 h to go upstream from Luxor to Aswan, a distance of 208 km, and 19.2 h to make the return trip downstream. Assuming the ship’s speed relative to the water is the same in both cases, calculate the speed of the current in the

> How much work is done on the bowstring of Example 6.9 to draw it back by 20.0 cm? [Hint: Rather than recalculate from scratch, use proportional reasoning.]

> You are on the Moon and would like to send a probe into space so that it does not fall back to the surface of the Moon. What launch speed do you need?

> Each prong of a vibrating tuning fork moves back and forth quite precisely in simple harmonic motion. The distance the prong moves between its extreme positions is 2.24 mm. If the frequency of the tuning fork is 440.0 Hz, what are the maximum velocity an

> A proton in Fermilab's Tevatron is accelerated through a potential difference of 2.5 MV during each revolution around the ring of radius 1.0 km. In order to reach an energy of 1 TeV, how many revolutions must the proton make? How far has it traveled?

> A flat-bottomed barge, loaded with coal, has a mass of 3.0 × 105 kg. The barge is 20.0 m long and 10.0 m wide. It floats in freshwater. What is the depth of the barge below the waterline?

> Why is the muzzle of a rifle not aimed directly at the center of the target? Why is this more important at longer ranges?

> A spacecraft is in orbit around Jupiter. The radius of the orbit is 3.0 times the radius of Jupiter (which is RJ = 71 500 km). The gravitational field at the surface of Jupiter is 23 N/kg. What is the period of the spacecraft’s orbit? [Hint: You don’t ne

> Give a real example of the motion of some object for which: (a) the velocity and net force are in the same direction; (b) the velocity and net force are in opposite directions; (c) the velocity is nonzero and the net force is zero; (d) the velocity a

> While you are supervising playground activity during recess, the children are playing a game of tag. As Marlene and Shelly run past each other in opposite directions, Marlene reaches out and touches the shiny logo on Shelly’s jacket. Shelly starts to cry

> What is the potential energy if a third point charge q = −4.2 nC is placed at point a?

> You are given the task of designing a mechanism to trip a switch in an automobile seat belt, causing it to tighten in case of an accident. You decide that if the velocity of the car is high and constant the passenger is in no danger; it is only high acce

> Tell whether each of the following objects has a constant velocity and explain your reasoning. (a) A car driving around a curve at constant speed on a flat road. (b) A car driving straight up a 6° incline at constant speed. (c) The Moon in orbit aroun

> The mass of 1 mol of 13C (carbon-13) is 13.003 g. (a) What is the mass in u of one 13C atom? (b) What is the mass in kilograms of one 13C atom?

> If an object is acted on by two constant forces is it possible for the object to move at constant velocity? If so, what must be true about the two forces? Give an example.

> 31 to 33. Each row of the table describes an object moving along the x-axis. Based on the information given in two of the columns, choose the correct entry for the other columns. The question number is in parentheses. 34. A sailor climbs the mast in a b

> If an object is acted on by a single constant force, is it possible for the object to remain at rest? Is it possible for the object to move with constant velocity? Is it possible for the object’s speed to be decreasing? Is it possible for it to change di

> You have a simple pendulum and a mass-spring system in which the mass oscillates vertically. They both oscillate with the same period T. You take them both to the surface of the Moon, where the gravitational field is 1/6 that of Earth. (a) Is the period

> The seat on a carnival ride is fixed on the end of an 8.0 m long beam, pivoted at the other end. If the beam sweeps through an angle of 120°, what is the distance through which the rider moves?

> A sewing machine needle moves with a rapid vibratory motion, rather like SHM, as it sews a seam. Suppose the needle moves 8.4 mm from its highest to its lowest position and it makes 24 stitches in 9.0 s. What is the maximum needle speed?

> A parallel plate capacitor has a charge of 5.5 × 10−7 C on one plate and −5.5 × 10−7 C on the other. The distance between the plates is increased by 50% while the charge on each plate stays the same. What happens to the energy stored in the capacitor?

> Anthony is going to drive a flat-bed truck up a hill that makes an angle of 10° with respect to the horizontal direction. A 36.0 kg package sits in the back of the truck. The coefficient of static friction between the package and the truck bed is 0.380.

> 21. The four graphs show vx versus time. Which graph shows a changing ax that is always positive? 22. A boy plans to paddle a rubber raft across a river to the east bank while the current flows down river from north to south at 1 m/s. He is able to padd

> Using Newton’s laws, explain why a cord must exert forces of equal magnitude on the objects attached to each end, assuming that the cord’s mass is negligibly small.

> You are driving a car through campus when a fellow student steps out in front of you. You slam on the brakes, creating a 9.0 m long skid mark as measured by the police officer standing on the corner. She also has a device that measures the coefficient of

> 11. What is the average velocity of the jogger during the 30.0 min? (a) 1.3 m/s, north (b) 1.7 m/s, north (c) 2.1 m/s, north (d) 2.9 m/s, north 12. What is the average speed of the jogger for the 30 min? (a) 1.4 m/s (b) 1.7 m/s (c) 2.1 m/s (d) 2.9 m/s

> A person climbs from a Paris metro station to the street level by walking up a stalled escalator in 94 s. It takes 66 s to ride the same distance when standing on the escalator when it is operating normally. How long would it take for him to climb from t

> Refer to Conceptual Question 17 in Chapter 2. A heavy lead ball hangs from a string attached to a sturdy wooden frame. A second string is attached to a hook on the bottom of the lead ball. In Chapter 2, you imagined pulling slowly and steadily on the low

> 1. The term force most accurately describes (a) the mass of an object. (b) the inertia of an object. (c) the quantity that causes displacement. (d) the quantity that keeps an object moving. (e) the quantity that changes the velocity of an object. 2. A s

> Name a situation in which the speed of an object is constant while the velocity is not.

> A copper wire has a resistance of 24 Ω at 20°C. An aluminum wire has 3.0 times the length and 2.0 times the radius of the copper wire. (a) What is the resistance of the aluminum wire at 20°C? (b) The graph show

> What is the maximum electric energy density possible in dry air without dielectric breakdown occurring?

> An RLC series circuit has a resistance of R = 325 Ω, an inductance L = 0.300 mH, and a capacitance C = 33.0 nF. (a) What is the resonant frequency? (b) If the capacitor breaks down for peak voltages in excess of 7.0 × 102 V, what is the maximum source

> A horizontal towrope exerts a force of 240 N due west on a water- skier while the skier moves due west a distance of 54 m. How much work does the towrope do on the water-skier?

> A compass is placed directly on top of a wire (needle not shown). The current in the wire flows to the right. Which way does the north end of the needle point? Explain. (Ignore Earth's magnetic field.)

> A positively charged rod is brought near two uncharged conducting spheres of the same size that are initially touching each other (diagram a). The spheres are moved apart, and then the charged rod is removed (diagram b). (a) What is the sign of the net

> In the Davisson-Germer experiment (Section 28.2), the electrons were accelerated through a 54.0 V potential difference before striking the target. (a) Find the de Broglie wavelength of the electrons. (b) Bragg plane spacings for nickel were known at th

> A 10 kg baby sits on a three-legged stool. The diameter of each of the stool’s round feet is 2.0 cm. A 60 kg adult sits on a four-legged chair that has four circular feet, each with a diameter of 6.0 cm. Who applies the greater pressure to the floor and

> A hollow metal sphere carries a charge of 6.0 µC. An identical sphere carries a charge of 18.0 µC. The two spheres are brought into contact with each other, then separated. How much charge is on each?

> A runner is practicing on a circular track that is 300 m in circumference. From the point farthest to the west on the track, he starts off running due north and follows the track as it curves around toward the east. (a) If he runs halfway around the tra

> On the x-axis, in which of the three regions x 3d is there a point where ? Explain.

> Are there any points not on the x-axis where ? / Explain.

> What is the electric field at x = 2d (point S)?

> What is the electric field at x = d (point P)?

> Rank points A-E in order of the magnitude of the electric field, from largest to smallest.

> A 2010 kg elevator moves with a downward acceleration of 1.50 m/s2. What is the tension in the cable that supports the elevator?

> When the string of a guitar is pressed against any fret, the shortened string vibrates at a fundamental frequency 5.95% higher than when the previous fret is pressed. If the whole length of the section of string that can vibrate is 64.8 cm, how far from

> During a Compton scattering experiment, an electron that was initially at rest recoils at 180° (i.e., in the direction of motion of the incident x-ray photon). If the recoil electron has a kinetic energy of 0.20 keV, what is the wavelength of the inciden

> An electron traveling horizontally from west to east enters a region where a uniform electric field is directed upward. What is the direction of the electric force exerted on the electron once it has entered the field?

> What are the magnitude and direction of the electric field midway between two point charges, −15 µC and +12 µC, that are 8.0 cm apart?

> A van de Graaff generator has a metal sphere of radius 15 cm. To what potential can it be charged before the electric field at its surface exceeds 3.0 × 106 N/C (which is sufficient to break down dry air and initiate a spark)?

> The St. Charles streetcar in New Orleans starts from rest and has a constant acceleration of 1.20 m/s2 for 12.0 s. (a) Draw a graph of vx versus t. (b) How far has the train traveled at the end of the 12.0 s? (c) What is the speed of the train at the

> Section 29.8 states that the total energy released by the proton-proton cycle is the same as that released by the carbon cycle CNO-I. Why must the total energy released be the same?

> An equilateral triangle has a point charge +q at each of the three vertices (A, B, C). Another point charge Q is placed at D, the midpoint of the side BC. Solve for Q if the total electric force on the charge at A due to the charges at B, C, and D is zer

> (a) Show that the ground-state energy of the hydrogen atom can be written E1 = −ke2/(2a0), where a0 is the Bohr radius. (b) Explain why, according to classical physics, an electron with energy E1 could never be found at a distance greater than 2a0 from

> Using the three point charges of Example 16.3, find the magnitude of the force on q1 due to the other two charges, q2 and q3. [Hint: After finding the force on q1 due to q2, separate that force into x- and y-components.]

> To test hearing at various frequencies, a resonant RLC circuit is connected to a speaker. The resonant frequency is selected by changing a variable capacitor. (a) For an RLC circuit with L = 300 mH, what is the necessary capacitance to achieve a resonan

> Harrison traveled 2.00 km west, then 5.00 km in a direction 53.0° south of west, then 1.00 km in a direction 60.0° north of west. (a) In what direction, and for how far, should Harrison travel to return to his starting point? (b) If Harrison returns di

> Two Styrofoam balls with the same mass m = 9.0 × 10−8 kg and the same positive charge Q are suspended from the same point by insulating threads of length L = 0.98 m. The separation of the balls is d = 0.020 m. What is the c

> A total charge of 7.50 × 10−6 C is distributed on two different small metal spheres. When the spheres are 6.00 cm apart, they each feel a repulsive force of 20.0 N. How much charge is on each sphere?

> In a DNA molecule, the base pair adenine and thymine is held together by two hydrogen bonds (see Fig. 16.5). Let’s model one of these hydrogen bonds as four point charges arranged along a straight line. Using the information in the figu

> A K+ ion and a Cl− ion are directly across from each other on opposite sides of a cell membrane 9.0 nm thick. What is the electric force on the K+ ion due to the Cl− ion? Ignore the presence of other charges.

> Two point charges are separated by a distance r and repel each other with forces of magnitude F. If their separation is reduced to 0.25 times the original value, what is the magnitude of the forces of repulsion?

> An arrangement of two pulleys, as shown in the figure, is used to lift a 48.0 kg crate a distance of 4.00 m above the starting point. Assume the pulleys and rope are ideal and that all rope sections are essentially vertical. (a) What is the change in the

> In the figure, a third point charge −q is placed at point P. What is the electric force on −q due to the other two point charges?

2.99

See Answer