Over time, the types of technology can vary and be improved upon so that more advanced techniques become more valued. This could be the situation with mining whereby back in the 1500's in underground mines the rock was broken by fire setting ie lighting a fire below the rock face to heat up the rock and then throwing cold water on it to crack it, so that it could be dug by hand. With the advent of explosives, this all changed so that the rock could be blasted. The increase in advance rates for an underground heading have thus gone from 5-20 feet per month to up to 300meters (984 ft) per month for a 24/7 mining operation, which is a huge improvement.
Answer: 0.333 h
Explanation:
This problem can be solved using the <u>Radioactive Half Life Formula</u>:
(1)
Where:
is the final amount of the material
is the initial amount of the material
is the time elapsed
is the half life of the material (the quantity we are asked to find)
Knowing this, let's substitute the values and find 
from (1):
(2)
(3)
Applying natural logarithm in both sides:
(4)
(5)
Clearing :
(6)
Finally:
This is the half-life of the Bismuth-218 isotope
Answer:
the weight of alien is 200 newtons
Explanation:
The computation of the alien weight is shown below:
Given that
Acceleration = 20m/sec^2
And, the mass is 10 kg
So, the weight of alien is
= 20 × 10
= 200 newtons
hence, the weight of alien is 200 newtons
Answer:
Issac Newton was the first to use a glass prism to obtain the spectrum of sunlight. He tried to split the colours of the spectrum of white light further by using another similar prism. However, he could not get any more colours. He then placed a second identical prism in an inverted position with respect to the first as shown.
This allowed all the colours of the spectrum to pass through the second prism. He found a beam of white light emerging from the other side of the second prism. This observation gave Newton the idea that the sunlight is made-up of seven colours.
Explanation:
