A 10.0 kg box is dragged 5.00 meters across a rough horizontal floor by a rope with a tension of 45.0 N that makes an angle of 20.0 degrees to the horizontal. If the box started with a
speed of 3.00 m/s and ended with a speed of 5.00 m/s, what was the NET work done on the
box?

Unpolarized light of intensity i_0=750w/m^2 is incident upon two polarizers. after passing through both polarizers the intensity is i_2=280w/m^2. (a) what is the intensity of the light after it passes through the first polarizer in w/m^2? (b) write an equation for the angle between the polarizers in terms of the initial (i_0) and final (i_2) intensities. (c) find the angle between the polarizers in degrees.

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?

An electron in an x-ray machine is accelerated through a potential difference of 1.00 × 104 v before it hits the target. what is the kinetic energy of the electron in electron volts?