30 points if you ask in 5 minutes why is it impossible to create a perpetual motion machine? energy will eventually be converted into heat and the machine will burn up. some of the energy will always be lost in the conversion and therefore it will eventually stop. the friction that exists within machines will eventually cause the levers to break. it is not impossible; perpetual motion machines already exist.

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?

How is the acceleration of an object in uniform circular motion constant? a - in magnitude only b - in direction only c - in both magnitude and direction d - in magnitude, direction & orientation

Two point charges are separated by a certain distance. how does the strength of the electric field produced by the first charge