Air pressure describes: the weight of air molecules pushing side way on earth
the weight of air molecules pushing up on earth
the weight of air molecules pressing down on earth
the weight of air molecules pressing on earth

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.

Most short-period comets do not have randomly oriented orbits because

Abar magnet cut in half will form a total ofpoles.a)fourb)eightc)two