Huda runs 1000 meters using a force of 210 Newtons and a power output of 500 Watts, How long does it take Huda to complete the run?

When someone slams her books on a table the kinect energy is transferred into vibrations that travel to your ears as sound waves which statement describes the movement of those waves

Abearing is designed to a reduce friction b. support a load c.guide moving parts such as wheels, shafts and pivots d. all of the above

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.