The work function for metallic caesium is 2.24 ev. calculate the kinetic energy and speed of electrons ejected if a light source of a) 250 nm and b) 600 nm is used.

Rubber on floor tile has a coefficient of kinetic friction of 1.0 and a coefficient of static friction of 2.0. how much force would a 3.5 lb. robot need to produce in order to start moving?

Aboxcar traveling at 12 m/s approaches a string of 5 identical boxcars sitting stationary on the track. the moving boxcar collides and links with the stationary cars and they all move off together along the track. what is the final speed of the cars immediately after the collision? (you may take the mass of each boxcar to be 18,537 kg.)

Power can be defined as a. the distance over which work was done. b. how much work can be done in a given time. c. all the work in an given area. d. the energy required to do work.