Tennis balls traveling at greater than 100 mph routinely bounce off tennis rackets. at some sufficiently high speed, however, the ball will break through the strings and keep going. the racket is a potential-energy barrier whose height is the energy of the slowest string-breaking ball. suppose that a 100 g tennis ball traveling at 200 mph is just sufficient to break the 2.0-mm-thick strings. estimate the probability that a 120 mph ball will tunnel through the racket without breaking the strings. give your answer as a power of 10 rather than a power of e.

Unpolarized light falls on two polarizer sheets whose transmission axes are at right angles. a third polarizer is placed between the first two so that its axis makes a 52-degree angle with the axis of the first polarizer. a) what fraction of the incident light intensity is transmitted through the first polaroid? b) what fraction of the incident light intensity is transmitted through the second polaroid? c) what is the angle of polarization of the light that enters the third polaroid? d) what fraction of the incident light intensity is transmitted through the third polaroid. e) what happens if the middle polaroid is removed?

The electronic structure or chlorine is 2.8.7 what is the electronic structure of fluorine?

What component of earth’s atmosphere exists entirely as a result of photosynthesis?