HELP HELP HELP To fully describe the ejection of electrons from a metal's surface, scientists
must consider which of the following to be quantized?
A. Both light and matter
B. Neither light nor matter
C. Light only
O D. Matter only

The experiment done in lab is repeated, using a ball that has unknown mass m. you plot your data in the form of f 2 versus m/l, with f in rev/s, m in kg, and l in m. your data falls close to a straight line that has slope 3.19 m/(kg · s2). use g = 9.80 m/s2 and calculate the mass m of the ball.

The frequency of the fundamental of the guitar string is 320 hz. at what speed v do waves move along that string?

Abatter hits a 0.140-kg baseball that was approaching him at 30 m/s and, as a result, the ball leaves the bat at 40 m/s in the reverse of its original direction. the ball remains in contact with the bat for 2.0 ms. what is the magnitude of the average force exerted by the bat on the ball?