A car drives at a constant speed of 3 m/s around a circle with radius 20 m. What is the centripetal acceleration of the car?
A. 0.45 m/s2
B. 0.15 m/s2
C. 6.7 m/s2
D. 9.2 m/s2

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.

Light traveling in a medium with a refractive index 1.19 is incident on a plate of another medium with index of refraction 1.79. at what angle of incidence is the reflected light fully polarized?

What is the measurement of how fast an object moves relative to a reference point?