Which describes how a simple machine can make work easier ?
a.) it magnifies the kinetic energy so that the potential energy is greater
b.) it magnifies the potential energy so that the kinetic energy is greater
c.) it magnifies the output force so that the input force is greater
d.) it magnifies the input force so that the output force is greater

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.

If we relied solely on the nonrenewable resources found in the u. s., which one would we run out of first at current usage levels? a. natural gas b. oil c. uranium d. coal

Panel bc in fig. p2.76 is semi-circular, with the 3 meter radius and horizontal straight edge through point b. compute (a) the hydrostatic force of the water on the panel, (b) its center of pressure, and (c) the moment of this force about point b. assume atmospheric pressure on the dry side of the panel