Sandy puts a paper clip on the table. then, she puts a magnet near the paperclip. the paperclip begins to move. the paperclip has forces acting on it. a. unbalanced b. balanced c. only magnetic d. only gravitational

The of a machine determines its "usefulness." a. input force b. output force c. mechanical advantage

John throws .4 kg ball with velocity of 18 m/s. hits .2 kg bottle and bottle flies 25 m/s. how fast is ball traveling after hitting the bottle?

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?