A bar magnet is divided in two pieces. Which of the following statements is true?
A) The bar magnet is demagnetized.
B) The magnetic field of each separated piece becomes stronger.
C) The magnetic poles are separated.
D)Two new bar magnets are created.
E) The electric field is created

Write short note on the following ; collision theory, rotation angle and angular velocity, centripetal acceleration, coriolis force, and newton's law of gravitation.

The graph describes the motion of an object. the object moves with from a to b. it from b to c. it moves with from c to d.

The ratio of lift to drag l/d for a wing or airfoil is an important aerodynamic parameter, indeed, it is a direct measure of the aerodynamic efficiency of the wing. if a wing is pitched through a range of angle of attack, l/d first increases, then goes through a maximum, and then decreases. consider an infinite wing with an naca 2412 airfoil. estimate the maximum value of l/d. assume that the reynolds number is 9x10^6.