Arunner circles the track exactly 2 times for distance of 800m. it takes 4.0min. what is her average speed in m/s? what is her average velocity?

What is the earliest point in the universe that we can observe? why can’t we see back further than this?

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 mini-refrigerator fire was most likely caused by what type of wiring?