A piece of copper wire is placed in a beaker containing a solution of silver nitrate. Which statement is an observation? A. A chemical reaction is taking place. B. Silver metal forms on the copper wire. C. The solution begins to turn blue. D. Silver ions displace copper atoms.

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.

Abaseball is thrown from the outfield toward the catcher. when the ball reaches its highest point, which statement is true? (a)its velocity is not zero, but its acceleration is zero. (b) its velocity and its acceleration are both zero. (c) its velocity is perpendicular to its acceleration. (d) its acceleration depends on the angle at which the ball was thrown. (e) none of the above statements are true.

Petroleum contains energy. a. light b. kinetic c. chemical d. mechanical