If 20 beats are produced within one second, which of the following frequencies could possibly be held by two sound waves traveling through a medium along a common path at the same time?

a. 38 hz and 63 hz
b. 22 hz and 42 hz
c. 47 hz and 55 hz
d. 18 hz and 26 hz

**urgent** roberto plans to use two transformers to reduce a voltage of 120 v to 4 v. he uses a transformer that has 300 coils in the primary winding and 50 coils in the secondary winding. he has four other transformers, as listed in the table. which transformer should roberto use to have an ending voltage of 4 v? a- w b-xc- yd- z

What pressure difference is required between the ends of a 2.0-m-long, 1.0-mm-diameter horizontal tube for 40 c water to flow through it at an average speed of 4.0 m/s?

Difference between series and parallel circuits