The speed of a moving bullet can be determined by allowing the bullet to pass through two rotating paper disks mounted a distance
81 cm apart on the same axle. From the
angular displacement 18 ◦
of the two bullet
holes in the disks and the rotational speed
603 rev/min of the disks, we can determine
the speed of the bullet.
What is the speed of the bullet? Answer in units of m/s.

Atrain is traveling at 30.0 m/s relative to the ground in still air. the frequency of the note emitted by the train whistle is 262 hz. the speed of sound in air should be taken as 344 m/s. what frequency (f approach) is heard by a passenger on a train moving at a speed of 18.0 m/s relative to the ground in a direction opposite to the first train and approaching it? what frequency (f recede) is heard by a passenger on a train moving at a speed of 18.0 m/s relative to the ground in a direction opposite to the first train and receding from it?