Answer:v=3.28 m/s
Explanation:
Given
mass of rock 
diameter of circle 
radius 
At highest Point

At highest Point N=0 because mass is just balanced by centripetal Force
thus 




knowledge of first aid ... eg St John Ambulance, Red Cross etc. I think that everyone in a school should be taught First Aid.
Answer:
We feel cold when tap or well water in winter because heat flows from hot body to cold body.
Explanation:
Our <em>body</em><em> </em><em>is</em><em> </em><em>in</em><em> </em><em>optimal</em><em> </em><em>status</em><em> </em><em>is</em><em> </em><em>a</em><em> </em><em>hot</em><em> </em><em>body</em><em> </em><em>and</em><em> </em><em>tap</em><em> </em><em>or</em><em> </em><em>we</em><em>ll</em><em> </em><em>water</em><em> </em><em>is</em><em> </em><em>a</em><em> </em><em>cold</em><em> </em><em>body</em><em>.</em><em> </em><em>Theref</em><em>ore</em><em> </em><em>we</em><em> </em><em>feel</em><em> </em><em>cold</em><em>.</em>
Answer:
Micro and radio waves.
Lower energy.
Gamma rays.
Explanation:
The electromagnetic spectrum is the range of frequencies of electromagnetic radiation and their respective wavelengths.
Ionising radiation os defined as the energy required of photons of a wave to ionize atoms, causing chemical reactions.
The energy of the wave depends on both the amplitude and the frequency. If the energy of each wavelength is a discrete packet of energy, a high-frequency wave will deliver more of these packets per unit time than a low-frequency wave. In summary, the longer the wavelength, the lower the energy to ionise.
The velocity of a wave is directly proportional to the frequency of that wave.
c = f * lambda
Where,
c = velocity of the wave
f = frequency of the wave = 1/time
Lambda = wavelength.
From the above expression, the longer the wavelength, lambda the shorter the frequency.
Examples of waves with longer wavelengths are, micro and radio waves, while radiations with shorter wavelengths like gamma rays.