Two events are simultaneous to an observer. Which is true? They will generally also be simultaneous to other observers who move relative to the first observer. They will generally not be simultaneous to other observers who move relative to the first observer. They will always be separated in time to other observers whether they move relative to the first observer or not.
Frame S′ passes frame S in the usual way (positive directions). A beam of light also travels in the positive direction. Which is true? The light's speed relative to S is equal to its speed relative to S′. The light's speed relative to S is less than its speed relative to S′. The light's speed relative to S is greater than its speed relative to S′.
Which is true about the detected frequency and wavelength of light that is emitted by a source that is moving toward the detector? The frequency and wavelength are both greater than the proper values, as measured on the source. The frequency and wavelength are both smaller than the proper values of the emitted light, as measured on the source. The frequency is greater than the proper frequency and the wavelength is smaller than the proper wavelength. The frequency is smaller than the proper frequency and the wavelength is greater than the proper wavelength.
Which is true? A photon with frequency f can have any energy. A photon's energy is restricted to a value of hf. A photon's energy can be any integer multiple of hf.
How does the shift in the x ray wavelength depend on the angle at which the x ray scatters? increases with an increase in angle stays the same with an increase in angle decreases with an increase in angle
Which is true about the Schrödinger equation? It applies to electrons at any physically possible speed (v < c). It applies to only relatively fast electrons (v ≈ c). It applies to only relatively slow electrons (v < < c).
An electron is within a one-dimensional, infinite potential well. Which is true about the integral of the probability density from one wall to the other? The value of the integral is the same for any value of n. The value of the integral increases as we consider larger values of n. The value of the integral decreases as we consider larger values of n.
In a Bohr-model hydrogen atom, what force holds the electron in orbit around the proton? a gravitational force that is radially inward, toward the proton a gravitational force that is radially outward, away from the proton an electric force that is radially outward, away from the proton an electric force that is radially inward, toward the proton
If we decrease the size of a quantum dot that contains an electron, what happens to the energy levels? increase remain the same decrease
While flying toward Earth at 0.950 c (where c is the speed of light), a spaceship fires a missile which moves rearward at −282000000 m/s relative to the ship. What is the velocity of the missile relative to Earth? Define your coordinates so that positive velocities are directed away from Earth. m/s
In the classical limit, the relativistic transformation of velocities reduces to the same velocity in both frames. the Galilean transformation. zero. the speed of light.
The work function for a certain sample is 2.3 eV. The stopping potential for electrons ejected from the sample by 7.0×1014 Hz electromagnetic radiation is 2.9 V 2.3 V 0.59 V 0 V 5.2 V
Two astronauts travelling through space in opposite directions along the x-axis pass each other. Each measures the other to be moving past him at 0.99c. Each of them also carries a meter stick which has been measured to be 1.000000 m long in one's own frame. Which statement describes how they view the meter stick aboard the other ship? Both observe the meter stick aboard the other ship to be longer than their own. Both observe the meter stick aboard the other ship to be shorter than their own. The astronaut moving in the +x direction observes the meter stick aboard the other ship to be shorter than 1.0 m , while the astronaut moving in the x direction observes the other meter stick to be longer than 1.0 m . Both observe the meter stick aboard the other ship to be the same length as their own.
If the kinetic energy of an electron moving within a potential energy well increases, its de Broglie wavelength stays the same. decreases. increases.
A spaceship is in the shape of a cube which measures 493. m along each edge (in its own reference frame). If you observe the ship to have a constant velocity of 0.910 c in the x-direction (where c is the speed of light), what volume would you infer for the ship? m3
An electron trapped in an infinite potential well tends to be found in the ground state. first excited state. second excited state. None of the choices are correct; it has an equal probability of existing in all energy states.
An object moves with velocity u in Frame O. Frame A moves to the Right at speed v relative to O, while Frame B moves to the left at speed v relative to Frame O. If we apply the Lorentz transformation for velocities to find the velocity of the object in Frame A and Frame B, we will find it has the same speed but opposite directions in A and B . it has a different velocity in A than in B. it has twice the velocity in A that it has in B it has the same velocity in A and in B.
The work function of a metal is 3.69 eV . What is the cutoff frequency of this metal? 4.79×1014 Hz 7.86×1014 Hz 6.63×1014 Hz 1.60×1014 Hz 8.91×1014 Hz
A starship traveling at 99% of the speed of light fires a missile at an enemy starship which is 312 m ahead and traveling at the same velocity. The missile, which is 4.0 m long as measured aboard the starship before it is fired, travels from the launcher at a speed 120 m/s faster than the ship. What does the length of the missile appear to be to the occupants of the enemy ship? meters
The ground state energy of an electron trapped in a 30.0 -pm wide infinite potential well is 418.8 eV. What is the ground state energy of an electron trapped in a 60.0 -pm wide potential well? 1675.2 eV 837.6 eV 209.4 eV 104.7 eV 418.8 eV
A spaceship is designed in the shape of a right triangle which is 517. m long in the x direction and 100 m long in the y direction (in its own reference frame). If you observe the ship to have a constant velocity of 0.530 c in the x direction (where c is the speed of light), what length would you measure for the side of the ship which forms the hypotenuse? m
Stan sees a particle move with speed 0.688 c at an angle of 30.0 degrees to the x-axis. If Ollie moves away from Stan by moving along the x-axis at a speed of 0.493 c, at what angle to the x-axis does Ollie see the particle move? degrees
A stream of electrons, each with a kinetic energy of 450 eV , is sent through a potential-free region toward a potential barrier of "height" 500 eV and thickness 0.300 nm. The stream consists of 1×1015 electrons. How many should tunnel through the barrier? Pick the closest answer. The electron mass is 9.10938×10−31 kg. 6×104 8×107 4×105 7×106 4×107 1×106 8×109 7×104 9×105 3×103
What is the probability of detection of an electron in the third excited state in a 1D infinite potential well of width L if the probe has width L/30.0 (that is relatively small) and is centered at 0.300 L from the left "wall"? Express the answer as a percentage. 3.05 8.11 2.30 1.73 1.93 0.197 0.50 0.751 0.095 9.71
The length of a spaceship is measured to be exactly 1/3 its rest length. (a) What is the speed parameter β of the spaceship relative to the observer's frame? (b) By what integer factor do the spaceship's clocks run slow, compared to clocks in the observer's frame? (a) Number Units (b) Number Units
The mass of a muon is 207 times the electron mass; the average lifetime of muons at rest is 2.26 μs. In a certain experiment, muons moving through a laboratory are measured to have an average lifetime of 7.15 μs. For the moving muons, what are (a) β (b) K, and (c) p? The rest energy of the electron is 0.511 MeV. (a) Number Units (b) Number Units (c) Number Units
Under ideal conditions, a visual sensation can occur in the human visual system if light of wavelength 550 nm is absorbed by the eye's retina at a rate as low as 105 photons per second. What is the corresponding rate at which energy is absorbed by the retina? Number Units
A sodium lamp emits light at the power P = 60.0 W and at the wavelength λ = 565 nm, and the emission is uniformly in all directions. (a) At what rate are photons emitted by the lamp? (b) At what distance from the lamp will a totally absorbing screen absorb photons at the rate of 1.00 photon/cm2s? (c) What is the rate per square meter at which photons are intercepted by a screen at a distance of 1.70 m from the lamp? (a) Number Units (b) Number Units (c) Number Units
In a photoelectric experiment using a sodium surface, you find a stopping potential of 2.01 V for a wavelength of 290 nm and a stopping potential of 0.885 V for a wavelength of 393 nm. From these data find (a) a value for the Planck constant, (b) the work function Φ for sodium, and (c) the cutoff wavelength λ0 for sodium. (a) Number Units (b) Number Units (c) Number Units
An electron is trapped in a one-dimensional infinite potential well. For what (a) higher quantum number and (b) lower quantum number is the corresponding energy difference equal to 7 times the energy difference E43 between the levels n4 and n3? (c) Can a pair of adjacent levels have an energy difference equal to 2E43? (a) Number Units (b) Number Units (c)
Weights 800 N and 400 N are connected by a thread and move along a rough horizontal plane under the action of a force of 500 N applied to 800 N weight as shown in Fig 12. The coefficient of friction between the sliding surface of the weights and the plane is μ = 0.25. Determine the acceleration of the weights and tension in the thread, using work-energy equation. Fig. 12
A block of mass m1 = 8 kg that is free to move along a horizontal frictionless table, is connected by a string that wraps over a frictionless pulley to a second block of mass m2 = 3 kg which is hanging above the ground. The table is accelerating upward with constant acceleration a0 = 2 m/s2. a. At which acceleration does block m2 falls relative to the table (that is, relative to an observer that is standing on the table)? One possible correct answer is: 3.2181818181818 Now the table is accelerated to the right with acceleration a0, as seen in the figure: b. What will be the downward acceleration of block m2 relative to the table in this case? One possible correct answer is: 1.2181818181818
Figure below shows a simplified route of a roller coaster. Initially, the cart runs down from the starting point. Neglecting the effects of friction, find its speed at (a) the "valley" V (b) at the top of second hill L (c) If friction is taken in consideration, will the answers be smaller or larger than that found in part (a) and (b)?
Assume the three blocks ( m1 = 1.0 kg, m2 = 2.0 kg, and m3 = 4.0 kg) portrayed in the figure below move on a frictionless surface and a force F = 44 N acts as shown on the 4.0 kg block. (a) Determine the acceleration given this system (in m/s2 to the right). m/s2 (to the right) (b) Determine the tension in the cord connecting the 4.0 kg and the 1.0 kg blocks (in N ). N (c) Determine the force exerted by the 1.0 kg block on the 2.0 kg block (in N ). N (d) What If? How would your answers to parts (a) and (b) of this problem change if the 2.0 kg block was now stacked on top of the 1.0 kg block? Assume that the 2.0 kg block sticks to and does not slide on the 1.0 kg block when the system is accelerated. (Enter the acceleration in m/s2 to the right and the tension in N .) acceleration m/s2 (to the right) tension N
The figure shows an overhead view of a ring that can rotate about its center like a merry-go-round. Its outer radius R2 is 0.9 m , its inner radius R1 is R2 /2, its mass M is 7.4 kg , and the mass of the crossbars at its center is negligible. It initially rotates at an angular speed of 8.9 rad/s with a cat of mass m = M/4 on its outer edge, at radius R2. By how much does the cat increase the kinetic energy of the cat-ring system if the cat crawls to the inner edge, at radius R1? Number Units
A particle is acted on by two torques about the origin: τ→, has a magnitude of 6.5 N⋅m and is directed in the positive direction of the x axis, and τ→2 has a magnitude of 2.3 N⋅m and is directed in the negative direction of the y axis. In unit-vector notation, find dℓ→/dt, where ℓ→ is the angular momentum of the particle about the origin. Number i^ j^ Units
Two bumper cars at the county fair are sliding toward one another (see figure below). Initially, bumper car 1 is traveling to the east at 5.62 m/s, and bumper car 2 is traveling 60.0∘ south of west at 10.00 m/s. After they collide, bumper car 1 is observed to be traveling to the west with a speed of 3.28 m/s. Friction is negligible between the cars and the ground. (a) If the masses of bumper cars 1 and 2 are 592 kg and 633 kg respectively, what is the velocity of bumper car 2 immediately after the collision? (Express your answer in vector form. Enter your answer to at least three significant figures.) v→2 = m/s (b) What is the kinetic energy lost in the collision?
A uniform disk of mass 351 kg and radius 0.26 m is mounted on frictionless bearings so it can rotate freely around a vertical axis through its center (see the following figure). A cord is wrapped around the rim of the disk and pulled with a force of 10 N. (a) How much work (in J) has the force done at the instant the disk has completed four revolutions, starting from rest? J (b) Determine the torque due to the force. (Enter the magnitude in N⋅m.) N⋅m Calculate the work (in J) done by this torque at the instant the disk has completed four revolutions. J (c) What is the angular velocity (in rad/s) at that instant? (Enter the magnitude.) rad/s (d) What is the power output (in W) of the force at that instant? W
A luge and its rider, with a total mass of 84.0 kg , emerge from a downhill track onto a horizontal straight track with an initial speed of 31.0 m/s. If a force slows them to a stop at a constant rate of 2.30 m/s2, (a) what magnitude F is required for the force, (b) what distance d do they travel while slowing, and (c) what work W is done on them by the force? What are (d) F, (e) d, and (f) W if they, instead, slow at 4.60 m/s2? (a) Number Units (b) Number Units (c) Number Units (d) Number Units (e) Number (f) Number Units