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
Answer:
(B) Dark energy does not exist and there is much more matter than current evidence suggests.
Explanation:
The repulsive force which is accelerating expansion of the universe is called as dark energy. Most of matter present in the universe is the dark matter of about eighty five percent.
So, a collapsing universe would not have the dark energy and there is more matter which is not the dark matter. This theory is rejected because expansion of the universe is observable.
Answer:
The correct option is;
Sweet Potatoes
Explanation:
The dietary fiber in Corn = 2.7 g per 100 g
The dietary fiber in Mashed Potatoes = 1.3 g per 100 g
The dietary fiber in Sweet Potatoes = 3 g per 100 g
The dietary fiber in Pecan Pie = 2.1 g per 100 g
Therefore, the Thanksgiving dish that contains the most dietary fiber per 100 g is Sweet Potatoes