Acertain dog whistle operates at 23.5 khz, while another (brand x) operates at an unknown frequency. if humans can hear neither whistle when played separately, but a shrill whine of frequency 5000 hz occurs when they are played simultaneously, estimate the operating frequency of brand x.

Avery hard rubber ball (m = 0.5 kg) is falling vertically at 4 m/s just before it bounces on the floor. the ball rebounds back at essentially the same speed. if the collision with the floor lasts 0.05 s, what is the average force exerted by the floor on the ball?

The most important difference between a wedge and an inclined plane is a. their size b. their shape c. how they are used d. what they are made of

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.