An elastic cord is 61cm long when a weight of 75N hangs from it but is 85cm long when a weight o f 210N hangs from it. What is the spring constant k of this elastic cord

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.

Observations show that interstellar clouds can have almost any shape and

Frequency of electromagnetic waves that a radio station is assigned is called