A block slides with constant velocity down a rough inclined plane that makes an angle of 0 with the horizontal . It experiences three forces : gravitational (fg) , normal (FN), and frictional (Ff) which of the following gives the magnitude of the net force on the block A) zero
B) Ff+Fn-Fg
C)Fgcos0-Ff
D)Fg sin0 + Fn cos0 -Ff

Zeros that follow non-zeros numbers and are also to the right of a decimal point are significant

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?

Energy flows from the producer level to the level. is called