Answer:Half-life is the amount of time it takes for the initial mass of the isotope to decompose, by half, into other lighter atoms.
Explanation:Different radioactive isotopes have different half-lives. For example, the element technetium-99m has a half life of 6 hours. This means that is 100 kg of the element is left to decay, in 6 hours, 50kg of the mass will have changed into other elements/atoms. The half-life of uranium-238 is 4.5 billion years while that of polonium-216 is only 0.145 seconds.
Answer:
h = 16.67m
Explanation:
If the kinetic energy of the cylinder is 510J:


Where the inertia is given by:

Replacing this value:

Speed of the block will therefore be:

By conservation of energy:
Eo = Ef
Eo = 0

So,

Solving for h we get:
h=16.67m
Work done is the distance a force acts over.
So, the work done here is 9.0N * 3.0m = 27 J
Ok cool dude bro I just need to answer a question
The answer would be a reflection. This is because, t<span>he color of an object is actually the wavelengths of the light reflected while all other wavelengths are absorbed. Color, in this case, refers to the different wavelengths of light in the </span>visible light spectrum<span>perceived by our eyes. The physical and chemical composition of matter determines which wavelength (or color) is reflected.</span>