Force f = − + ( 8.00 n i 6.00 n j ) ( ) acts on a particle with position vector r = + (3.00 m i 4.00 m j ) ( ) .

what are

(a) the torque on the particle about the origin, in unit-vector notation
(b) the angle between the directions of r and f ?

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?

Which of the following are appropriate acceleration units?

How does an observation about an object differ from an inference about that object