If a dielectric is inserted bw the plates of a 20 microfarad capacitor, it's capacitance will be A. Remain same
B. Be doubled
C. Be halved
D. Become zero
(Ans with explanation please)

The speed of light in a material is 0.50 c. what is the critical angle of a light ray at the interface between the material and a vacuum?

In a game of pool, ball a is moving with a velocity v0 of magnitude v0 = 15 ft/s when it strikes balls b and c, which are at rest and aligned as shown. knowing that after the collision the three balls move in the directions indicated and assuming frictionless surfaces and perfectly elastic impact (that is, conservation of energy), determine the magnitudes of the velocities va, vb, and vc.

What is the quantity which is measured by the area occupied below the velocity- time graph?