The normal force equals the magnitude of the gravitational force as a roller coaster car crosses the top of a 33-mm-diameter loop-the-loop. part a what is the car's speed at the top? express your answer to two significant figures and include the appropriate units.

An air-filled capacitor is formed from two long conducting cylindrical shells that are coaxial and have radii of 26 mm and 103 mm. the electric potential of the inner conductor with respect to the outer conductor is - 700 v (k = 1/4πε 0 = 8.99 × 109 n · m2/c2) the energy stored in a 1.0-m length of this capacitor is closest to