Blue light (l = 460 nm) is incident on a piece of potassium (W = 2.45 eV). What is the maximum kinetic energy of the ejected photoelectrons? (h = 6.63 × 10^-34 J×s, c = 3.00 × 10^8 m/s, 1 eV = 1.60 × 10^-19 J, and 1 nm = 10-9 m)
a. 1.0 eV
c. 0.50 eV
b. 0.25 eV
d. 4.9 eV
B
You might also like to view...
A horizontally-projected beam of electrons travelling at 55 km/s travels between two parallel plates separated by 7.4 cm, and 12 cm long, between which there is an electric field of 7.2 mV/m upward. If the beam enters the region at a height of 3.7 cm above the lower plate, at what height above the lower plate is the beam when it exits? The electron mass is 
A. 0.9 cm B. 2.3 cm C. 5.1 cm D. 4.6 cm
A planet is much brighter than the star it orbits
a. True b. False Indicate whether the statement is true or false
Uniform Circular Motion: A 250-kg motorcycle goes around an unbanked turn of radius 13.7 m at a steady 96.5 km/h. What is the magnitude of the net force on the motorcycle?
A. 719 N B. 2.95 × 103 N C. 1.31 × 104 N D. 4.31 × 104 N
A 4.7-kg solid sphere, made of metal whose density is 4000 kg/ , hangs by a light cord. When the sphere is immersed in water, what is the tension force the cord exerts on the sphere? The density of water is 1000 kg/m3
A) 35 N B) 40 N C) 46 N D) 52 N E) 58 N