40 dB is 20 dB more power than 20 dB is. 20 dB more means 100 times as much.
Answer:
<em>1.Magnetic Force - Used in cranes to separate metal junk from junkyards.</em>
<em>2.Frictional Force- Helps us to walk.</em>
Answer:
The fraction of kinetic energy to the total energy is
.
Explanation:
displacement is one third of the amplitude.
Let the amplitude is A.
x= A/3
The kinetic energy of the body executing SHM is

The total energy is

Divide (1) by (2)

Answer:
Explanation:
Use the one-dimensional equation:
which says that the final velocity of a falling object is equal to its initial velocity times the acceleration of gravity times the time it takes to fall. We have the final velocity, -14.5 (negative because its direction is down and down is negative), initial velocity is 0 (because it was held still by someone before it was dropped), and acceleration is -9.8 (negative again, because direction is down while acceleration increases). Filling in:
-14.5 = 0 - 9.8t and
-14.5 = -9.8t so
t = 1.5 seconds