1)which statement best describes energy in an open system?

a) all energy and matter are contained within the system.

b) energy and matter flow into and out of the system.

c) matter flows into and out of the system; energy does not.

d) there is no energy in an open system; there is matter.

2)when a sound source is moving toward the observer, the observer will hear a

a) higher pitch due to the change to a lower frequency.

b) higher pitch due to the change to a higher frequency.

c) lower pitch due to the change to a higher frequency.

d) lower pitch due to the change to a lower frequency.

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.