PLEASE!!!! I need help with vibrations and waves for physics!!?

Question

1) What is the frequency, in hertz, that corresponds to each of the following periods?
a) 0.10s? __Hz
b) 4s? __Hz
c) 1/40s? __Hz

2)A skipper on a boat notices wave crests passing his anchor chain every 5 s. He estimates the distance between wave crests to be 15 m. He also correctly estimates the speed of the waves. What is this speed? __m/s

3)A mosquito flaps its wings 640 vibrations per second, which produces the annoying 640 Hz buzz. The speed of sound is 340 m/s. How far does the sound travel between wing beats? In other words, find the wavelength of the mosquito's sound. ____m

4)What is the period, in seconds, that corresponds to each of the following frequencies?
a) 9Hz ___s
b) 0.30Hz ___s
c) 60Hz ___s

5)Radio waves travel at the speed of light: 300000 km/s. What is the wavelength of radio waves received at 700 MHz on your radio dial? ___m

Answer 1

(1) Period is the reciprical of frequency

T = 1 / f or f = 1 / T

Plug in your periods and compute the frequencies.

(2) The wave equation is

f L = v

where f is the frequency, L the wavelength (the Greek letter lambda in your text), and v the velocity.

The period is 5 seconds. Now you also know the frequency using the relationship from (1). The wavelength is 15 meters. Compute the velocity using the wave equation.

(3) You are given velocity and frequency; compute wavelength using the wave equation.

(4) Same relationship as used in (1)

(5) You are given the velocity and the frequency; compute the wavelength using the wave equation.

Answer 2

my answer is a big ? mark after each question or write good question below each one lol sorry i cant be much help took physics two years ago and i have hit my head a too few many times since that