11. Cleats or spikes on shoes make friction because they provide a surface. 12. Rolling friction is than sliding friction. 13. Ball bearings purpose is to create friction. 14. In order for a train to move on the tracks there must be friction between the and the . 15. Heat shields on a space craft are necessary when it reenters the earth’s atmosphere because at the high speed of entry air will . 16. Crickets use friction to . 17. Mucous on slugs is remarkable because it’s both and . 18. When air molecules into each other they cause friction.

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.

What is a neurotransmitter involved in mood reward, addiction, and motor behaviors?

Examine the nuclear reacti why is this classified as a nuclear reaction rather than a chemical reaction? it is not balanced. a new compound is formed. a change has occurred in a nucleus. a new element has been formed.