Answer: A) O N
Explanation:
An object in motion will maintain its state of motion. The presence of an unbalanced force changes the velocity of the object.
Sound level at distance of 15 m is given as 20 dB
so intensity at this distance is given as



now if we move closer to some some distance the sound level is now 50 dB
now the intensity is given as



now we know that



so now the distance from friend must be 47 cm
The two factors that affect the period of a pendulum are the length of the string and the distance in which the pendulum falls.
Hope this helps! I would greatly appreciate a brainliest! :)
Answer:
The artifact is 11,460 years old.
<u>Explanation</u>:
Given that,
The half life of the carbon-14 is 5730 years and we are left with 255 of the sample of wood from an arti-fact.
So it takes 5730 years for the sample to reduce into half
Initially there will be 100% of the sample so
after first 5730 years, the sample reduces into 50% percent
Now the left 50% sample will take another 5730 years to decay into half of its amount.
after next 5730 years the sample reduces into 25% percent
So totally after 2 half-life the sample reduces into 25%
That is (5730 +5730) years = 11460 years