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:
f = 0.283
Explanation:
With the given values x=5m and t=2s, the acceleration a of the block must be:
(1)
The sum of all forces in the inclined plane must be:
(2)
Solving equation2 for the acceleration a:
(3)
Using equations 1 and 3 to solve for f: