Answer:E
Explanation:
It is given that Energy of gamma ray is E=1.2 Mev
Shielding effect can be measured by measuring the fraction of gamma rays blocked by shield. If certain thickness will able to block half the radiation then to block 75% radiation we need to add same amount of thickness in order to block the remaining radiation.
i.e.
fraction is blocked by 10 cm thickness
then remaining radiation is 
another 10 cm thickness will block the remaining half radiation i.e.
so total 75 % radiation will be blocked
The increase in entropy is directly related to the increase in temperature.
The net force is the 10N force and its direction is towards F2 force.
<h3>What is resultant force?</h3>
The resultant force or the net force is the actual force that acts on a body. We are told that the two forces act in opposite directions hence the net force is F2 - F1 = 30 N - 20 N = 10 N.
ii) The direction of this net force is going to be towards the 30N force.
iii) If the body does not move under the application of these forces then the F1 force must be reinforced by another force which balances it against the F2 force.
Learn more about net force:brainly.com/question/18031889?
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That's called a prototype, mainly used to save resources of the company or inventor. And used to look for flaws and perfect them to make the product more safe and efficient.
Answer:
The answer is a.
Explanation: Billions of years ago, there were lakes and rivers in the surface of mars because mars had a denser atmosphere and higher surface temperatures which allowed a vast amount of liquid water on the surface. Recently, most of the water on mars today exist as ice.