An airplane traveling at one third the speed of sound (i. e., 114 m/s) emits a sound of
frequency 3.76 kHz.
At what frequency does a stationary listener hear the sound as the plane approaches?
Answer in units of kHz.

What is the name for the remnant of an asymptotic giant that has lost its shells? black dwarf white dwarf yellow giant black hole

Name two kinds of practical electric pumps.

An athlete swings a ball, connected to the end of a chain, in a horizontal circle. the athlete is able to rotate the ball at the rate of 8.13 rev/s when the length of the chain is 0.600 m. when he increases the length to 0.900 m, he is able to rotate the ball only 6.04 rev/s. (a) which rate of rotation gives the greater speed for the ball? 6.04 rev/s 8.13 rev/s (b) what is the centripetal acceleration of the ball at 8.13 rev/s? m/s2 (c) what is the centripetal acceleration at 6.04 rev/s? m/s2