Physics Units Level: High School
An astronomical unit of distance is the light-year ,which is the distance light travels in one year . Compute this distance in meters . How many meters away is a star at a distance of 4 light-years from the earth ?
Physics Electromagnetic Induction Level: High School
What happens to the frequency and speed of an electromagnetic wave if its wavelength is doubled ?
Physics Magnetism,Magnetic Effects Of Current Level: High School
Force on a moving charge in a magnetic field
If the speed of a charged particle moving in a uniform magnetic field is doubled , what happens to the magnetic force on the particle ?
Physics Modern Physics Level: High School
Radioactivity
A radioactive element X decays to stable element Y . starting with a large pure sample of element X , after 5200 years the sample will be 81% element Y . the decay constant of element X is most nearly ( ) / yr .
Physics Magnetism,Magnetic Effects Of Current Level: High School
Force on a moving charge in a magnetic field
A particle is emitted due north into a uniform magnetic field that is directed vertically up . The particle is immediately / instantaneously deflected west . The particle is a: then explain .a) alpha
b) beta
c) gamma
d) neutron
e) proton
d) either alpha or a proton
g) more information is needed
Physics Ray Optics Level: High School
Refraction
A 5 cm green arrow (light source ) that points due north is placed directly in front of a vertical north/south convex lens at do = (0.8 x focal length), a smaller distance than f , the resulting image points : then explain.a) north
b) south
c) east
d) west
e) up
f) down
g) no image formed
Physics Ray Optics Level: High School
Refraction
A ray of red light in material #1 strikes an interface at an angle of 40 degree , and the ray of light enters material #2 at an angle of 50 degrees . As is crossed the interface the ray of light had its speed . Explain your reasoning .a) Decrease
b) Increase
c) Remain constant
d) Answer depends on the frequency of the light
Physics Electrostatics Level: High School
How you would know a nonzero field was present and how you would measure it ?
Physics Electrostatics Level: High School
Beams of high-speed protons can be produced in “guns” using electric field to accelerate the protons .a) What acceleration would a proton experience if the gun’s electric field were 2.00 x 10^4 N/C ?
b) What speed would the proton attain if the field accelerated the proton through a distance of 1.00 cm ?
Physics Electrostatics Level: High School
A plutonium-239 nucleus of radius 6.64 femptometers has an atomic number Z = 94 . Assuming that the positive charge is distributed uniformly within the nucleus , What are the magnitude and direction of the electric field at the surface of the nucleus ? Assume the influence of the positive charge at the nuclear surface is the same as that of a point charge .
Physics Modern Physics Level: High School
Bohr’s Atomic Model
Hydrogen emits a photon with wavelength lamda = 435 nm . Which transition between energy levels does this correspond to ?
Physics Modern Physics Level: High School
Bohr’s Atomic Model
What is the energy difference between an electron in n = 3 state and n = 5 state in hydrogen ? If the electron makes a transition from n = 5 to n = 3 this energy difference is carried away by a single photon . Calculate the wavelength expressed in nm , and the frequency of this emitted photon . In what part of the electromagnetic spectrum does it lie ?
Physics Modern Physics Level: High School
Photoelectric Effect
A Light of frequency 9.0 x 10^14 Hz incident on a metal surface is ejects photo-electrons having energy 1 eV . Calculate the work function W for this metal .
Physics Modern Physics Level: High School
Dual Nature
What is each of the following ?a) the wavelength of a 5.0 eV photon .
b) the de Broglie wavelength of a 5.0 eV electron .
Physics Modern Physics Level: High School
Diffraction of Sound
As section 27.5 discusses , sound waves diffract or bend around the edges of a doorway . Larger wavelengths diffract more than similar wavelengths .a) The speed of sound is 343 m / s . With what speed would a 54.6 kg person have to move through a doorway to diffract to the same extent as a 122 Hz bass tone ?
b) At the speed calculated in part (a) , how long (in years) would it take the person to move a distance of the meter ?
