A person's center of mass is easily found by having the person lie on a reaction board. A horizontal, 2.4-m-long, 6.1 kg reaction board is supported only at the ends, with one end resting on a scale and the other on a pivot. A 58 kg woman lies on the reaction board with her feet over the pivot. The scale reads 27 kg. What is the distance from the womanâs feet to her center of mass?

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.

Do you agree with scientist’s prediction about the warming of alaska and other polar regions?

Which diagram correctly demonstrates the various forces acting on a ball moving horizontally with some speed?