Physics is soo hard... will you plz show work on calculation problems too?

Question

1)A weight suspended from a spring is seen to bob up and down over a distance of 45 centimeters 6 times each second. What is its frequency in Hz? And whats the period in s? And whats the amplitude in cm?
2)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 in m?
3)A mosquito flaps its wings 610 vibrations per second, which produces the annoying 610 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 in meters.
4)On a keyboard, you strike a note, which has a frequency of 260 Hz.
(a) What is the period of one vibration of this tone?
s
(b) As the sound leaves the instrument at a speed of 340 m/s, what is its wavelength in air?
m

Answer 1

In problem 1, the answers are given to you. Frequency is the number of times in one second that you weight goes through one cycle of motion (from bottom to top back to bottom). So it has a frequency of 6 Hz. Period is how long it takes to do one cycle. If six cycles happen in one second, one cycle takes 1/6 of a second. Amplitude is half the distance from top of cycle to bottom of cycle so (45 cm)/2 = an easy calculation you can do on your own. This question simply is testing your knowledge of the definitions of the terms, I would advise that you study these definitions and know what each of the terms mean.

2. Speed of a wave is equal to wavelength times frequency. You have the frequency (700 MHz) and the speed (300,000 km /s) so you can find wavelength by dividing speed by frequency.

3. Same exact problem as number two only with different numbers.

4. a. Same as number 1
b. Same as number 2 and 3.