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:
a) f ’’ = f₀
, b) Δf = 2 f₀ 
Explanation:
a) This is a Doppler effect exercise, which we must solve in two parts in the first the emitter is fixed and in the second when the sound is reflected the emitter is mobile.
Let's look for the frequency (f ’) that the mobile aorta receives, the blood is leaving the aorta or is moving towards the source
f ’= fo
This sound wave is reflected by the blood that becomes the emitter, mobile and the receiver is fixed.
f ’’ = f’
where c represents the sound velocity in stationary blood
therefore the received frequency is
f ’’ = f₀
let's simplify the expression
f ’’ = f₀ \frac{c+v}{c-v}
f ’’ = f₀
b) At the low speed limit v <c, we can expand the quantity
(1 -x)ⁿ = 1 - x + n (n-1) x² + ...
f ’’ = fo
f ’’ = fo 
leave the linear term
f ’’ = f₀ + f₀ 2
the sound difference
f ’’ -f₀ = 2f₀ v/c
Δf = 2 f₀ 
Answer:
I believe the answer is speed up.
Explanation:
this is because when water heats up the molecules move father apart from each other they speed up, eventually causing the water to boll
The charge distribute on the inner surface with the radius r₁ will be zero,In the region r₁<r<r₂ will also zero. While on the outer surface with radius r₂ will be -q.
<h3>What is Gauss law?</h3>
The total electric flux out of a closed surface is equal to the charge contained divided by the permittivity,
According to Gauss Law. the electric flux in a given area is calculated by multiplying the electric field by the area of the surface projected in a plane perpendicular to the field.
From the Gauss law, it is stated that the field inside the conductor is zero. Charge will lie only on the surface.
(a)The charge distribute on the inner surface with the radius r₁ will be zero.
(b) In the region r₁<r<r₂ will also zero.
(c)The outer surface with radius r₂ charge distribution will be -q.
Hence, the charge distribute on the inner surface with the radius r₁ will be zero,
To learn more about the Gauss law, refer to the link;
brainly.com/question/2854215
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Explanation:
Force = Mass × Acceleration
Mass = 150kg
Acceleration = 5 m/s^2
Force = 150 × 5 = 750N