When a diver under the sea shines a beam of light towards the surface of the water the light does not pass through the water- air boundary into the air above but reflects into the sea. State the name of the phenomenon which occurs and briefly explain why it occurs.

Aparticle of mass m is projected with an initial velocity v0 in a direction making an angle α with the horizontal level ground as shown in the figure. the motion of the particle occurs under a uniform gravitational field g pointing downward. (a) write down the lagrangian of the system by using the cartesian coordinates (x, y). (b) is there any cyclic coordinate(s). if so, interpret it (them) physically. (c) find the euler-lagrange equations. find at least one constant of motion. (d) solve the differential equation in part (c) and obtain x and y coordinates of the projectile as a function of time. (e) construct the hamiltonian of the system, h, and write down the hamilton’s equations (canonical equations) of motion.

The slope of a velocity time graph over any interval of time gives the during that interval

Explain the comparisons between nature and packingtown that appears on pages 81 and 82 answer