What sound frequency could a human detect?

Question 11 of 13 (1 point) jump to question: a stairway, ladder, or ramp must be present in excavations in which of the following situations? a. all trenches must have access/egress b. the trench is more than 15 feet wide but only 1 ½ feet deep c. the trench is more than 4 feet deep and the devices must be within 25 feet of all workers

If frequency goes down, what happens to wavelength? does it get shorter or longer?

How long will it take a car traveling of a constant speed of 45m/s to cover the distance of a 2.5km?