The angular velocity of a gear is controlled according to ω = 79 − 5t2 where ω, in radians per second, is positive in the clockwise sense and where t is the time in seconds. Find the net angular displacement Δθ (poisitive in the clockwise sense) from the time t = 0 to t = 4 s. Also find the total number of revolutions N through which the gear turns during the 4 seconds.

Which lists the main components of darwin’s theory of evolution? a. random mutations drive evolution; the evolution of a population happens slowly; organisms have common ancestors; organisms do not change. b. natural selection drives evolution; the evolution of a population happens slowly; organisms have common ancestors; organisms change over time. c. natural selection drives evolution; the evolution of a population happens rapidly; organisms have common ancestors; organisms change over time. d. random mutations drive evolution; the evolution of a population happens rapidly; organisms have common ancestors; organisms do not change.

Consider an insulating crystal, made up of layers of atoms. what form would you expect the temperature dependence of the phonon heat capacity to approach at extremely low temperatures if the interlayer coupling is i)very strong (rigid coupling), and ii) very weak. explain.

Which of the following situations would produce an average velocity of zero? o a. a horse galloping in a field b. a round-trip to school and back o c. a trip, first to the moon, then onto mars o d. the criss-crossing path of a flying bug