Starting from the fermat’s principle derive an equation for a shape of an air-glass interface which collimate the rays from a point s0on the optical axis in air parallel to the optical axis in glass (ng=1.5).

An object is dropped from a tower, 400 ft above the ground. the object's height above ground t seconds after the fall is s(t)equals400 minus 16 t squared. determine the velocity and acceleration of the object the moment it reaches the ground. the velocity of the object the moment it reaches the ground is nothing ft/s.

Which of the following statement is false ? a. batteries should never be stored on metal trays or outside in the elements)b, battery acid cannot be neutralized)c. do not stack batteries on top of each other)d. never put a damaged battery in a dumpster. i

Does the distance travelled by an oscillating mass between times t=0 and t2 equal the displacement of the particle over the same time period if t2> t/2? hint: consider a sine wave starting at t1=0, then consider a closing wave starting at t1=0, for your explanation.