Answer:
hsjishhdhjs jdjyshskksndhu
Explanation:
Weight (N) = Mass * Acceleration
75.74 kg = Mass * 9.8 m/sec^2
Mass = 7.72 kg
Weight = 75.74 N
Given :
The light rays in the incident ray originate at 20º from the surface.
To Find :
The angle for the incident ray.
Solution :
We know angle of incidence is measured from perpendicular to the surface .
So,
Now, we know by law of reflection :
Angle of reflection = Angle of incident
Therefore, the angle of incident and reflection is 70° each.
That's right, the correct answer is
<span>A) The isotopes have a long half-life and only remain radioactive for a long time period
The half life of an isotope is the time it takes for the amount of the sample to reduce to half of its initial value. If an isotope has a long half-life, it means it takes a long time to reduce down to a significant level, so it will remain radioactive for a long time period.</span>
