Answer:
3
Explanation:
The half-life of a radioactive isotope is the time it takes for the mass of the sample to halve.
This can be rewritten as follows:
where
m(t) is the mass of the sample at time t
m0 is the original mass of the sample
n is the number of half-lives that passed
We see that if we take n=3, the amount of original sample left is
So 3 (3 half-lives) is the correct answer.
Answer:
1.) Frequency F = 890.9 Hz
2.) Wavelength (λ) = 0.893 m
Explanation:
1.) Given that the wavelength = 0.385m
The speed of sound = 343 m / s
To predict the frequency, let us use the formula V = F λ
Where (λ) = wavelength = 0.385m
343 = F × 0.385
F = 343/0.385
F = 890.9 Hz
2.) Given that the frequency = 384Hz
Using the formula again
V = F λ
λ = V/F
Wavelength (λ) = 343/384
Wavelength (λ) = 0.893 m
The two questions can be solved with the use of formula
Answer:
The electromagnetic force
Explanation:
The electromagnetic force is one of the four fundamental forces of nature. Namely, they are:
- Electromagnetic force: it is the force exerted between electrically charged particles (and between magnetic fields). The force can be either attractive (if the two charges have opposite signs) or repulsive (if the two charges have same sign), and it acts over an infinite range.
- Gravitational force: it is the force exerted between objects with mass. It is always attractive, and it also has an infinite range of action. It is the weakest of the four fundamental forces.
- Strong nuclear force: it is the force that acts between protons and neutrons inside the nucleus, and it is responsible for keeping the nucleus together and preventing it from breaking apart (due to the electrostatic repulsion between protons)
- Weak nuclear force: it is the force responsible for certains nuclear decays, such as the beta decay, in which a neutron turns into a proton, emitting an electron and an antineutrino.
Answer:
L= 12 light years
Explanation:
for length dilation we use the formula
now calculating Lo
Lo = 12.5×365×24×3600×3×10^8
= 1.183×10^17 m
now putting the values of v and Lo in the above equation we get
= 1.136×10^17 m
L= 
m
so L= 12 light years
