What is the energy of a photon whose frequency is 6.0 x 10^20?
(h=6.63 x10^-34 j•s; 1 eV=1.06x10^-19 J)

A. 1.6 MeV
B. 2.5 MeV
C. 3.3 MeV
D. 4.8 MeV

The charge on an electron is 1.60218 × 10−19 c and its mass is 9.10939 × 10−31 kg. how strong a magnetic field must be experienced by the electron if its path is a circle of radius 5.5 cm? answer in units of t.

Aspring is used to stop a 50-kg package which is moving down a 20º incline. the spring has a constant k = 30 kn/m and is held by cables so that it is initially compressed 50 mm. knowing that the velocity of the package is 2 m/s when it is 8 m from the spring and neglecting friction, determine the maximum additional deformation of the spring in bringing the package to rest.

"if the pressure acting on an ideal gas at constant temperature is tripled, its volume isa) reduced to one-third. b) increased by a factor of three. c) increased by a factor of two. d) reduced to one-half"