[celina10]

1) The recieving aerial for a UHF television is about 25cm long. This is one half of the wavelength of the transmission. Calculate the frequency of the transmission.

2) Two fishing floats, a distance of 4.5m apart, bob up and down at 20 times per minute. The floats always move in antiphase. There is always at least one wave crest between the floats, but never more than two.

a) Show that the wavelength of the ripples on the river is 3m, hence find the speed of the ripples on the surface.

b) Near the bank the depth of the river halves. the speed v of water waves in shallow water of depth d is given by v= (sqaure root)gd ,where g is 9.8ms-2
i) What is the new frequency and wavelength of the waves near the bank?
ii) What is the depth of the river near the bank?

Where do I even begin?

[Stonebridge]

Use the formula v=fλ

1) You are given λ. Radio waves travel at the speed of light.

[celina10]

(Original post by Stonebridge)
Use the formula v=fλ

1) You are given λ. Radio waves travel at the speed of light.

Really? Well that kind of solves everything. It doesn't say that in my text book, so what other waves in the electromagnetic spectrum travel at that speed?

[tasha96]

(Original post by celina10)
Really? Well that kind of solves everything. It doesn't say that in my text book, so what other waves in the electromagnetic spectrum travel at that speed?

All waves in the electromagnetic spectrum travel at the speed of light. (300 000 000 m/s)

[celina10]

(Original post by tasha96)
All waves in the electromagnetic spectrum travel at the speed of light. (300 000 000 m/s)

Thank you! I thought visible light only travelled at the speed of light.

[celina10]

(Original post by Stonebridge)
Use the formula v=fλ

1) You are given λ. Radio waves travel at the speed of light.

Ok I understand the first one now the answers 6 x 10^8 right?
But how would I go about solving the next one?