What is the major source of imperfection in a machine?

Which accounts for an increase in the temperature of a gas that is kept a constant volume

Review multiple-concept example 7 in this chapter as an aid in solving this problem. in a fast-pitch softball game the pitcher is impressive to watch, as she delivers a pitch by rapidly whirling her arm around so that the ball in her hand moves in a circle. in one instance, the radius of the circle is 0.626 m. at one point on this circle, the ball has an angular acceleration of 66.1 rad/s2 and an angular speed of 12.6 rad/s. (a) find the magnitude of the total acceleration (centripetal plus tangential) of the ball. (b) determine the angle of the total acceleration relative to the radial direction.

Which best term to describe a chemical reaction that absorbs energy from its surroundings? a.thermal conductor b.thermal insulator c.endothermic d.exothermic