You push very hard on a heavy desk, trying to move it. You do work on the desk:
(a) whether or not it moves, as long as you are exerting a force.
(b) only if it starts moving.
(c) only if it doesn't move.
(d) never—it does work on you.
(e) None of the above.
Ans: (b) only if it starts moving.
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How is the atmosphere of a planet affected by the rotation rate?
A) Faster rotation rates raise the atmospheric temperature. B) The rotation rate determines how long the planet is able to retain its atmosphere. C) The rotation rate determines how much atmosphere a planet has. D) Faster rotation rates produce stronger winds. E) Faster rotation rates raise surface temperatures and thus determine how much material is gaseous versus icy or liquid.
______________ faulting occurs as the result of forces parallel to the fault plane
Fill in the blank(s) with correct word
A 0.2-kg aluminum plate, initially at 20°C, slides down a 10-m long surface, inclined at a 30° angle to the horizontal. The force of kinetic friction exactly balances the component of gravity down the plane so that the plate, once started, glides down at constant velocity. If 90% of the mechanical energy of the system is absorbed by the aluminum, what is its temperature increase at the bottom
of the incline? (Specific heat for aluminum is 900 J/kg • °C.) a. 0.16°C c. 0.05°C b. 0.07°C d. 0.03°C
Most of the Rocky Mountains, in the western United States, lie in the ______________ Standard Time zone
a. Mountain b. Eastern c. Central d. Pacific