Answer:
1 x 10 -10 whisper at 1m distance.
Explanation:
- Properly fitted ear plugs an reduce noise form 15-30db. Although they are better for low frequency
The free electrons in metals can move through the metal, all while receiving and losing electrons, allowing metals to conduct electricity. Example: copper is a great conductor of electric current.
Answer:
D
Explanation:
D) The overall work done by gravity is zero
This statement is correct .
If m be the mass of each of the children and h be the height of tower
work done by gravity on the boys in going up = - mgh
it is so because force applied by gravity = mg downwards and displacement
is upwards
work done will be negative = - mgh
Work done by gravity on boys when they come down = + mgh because both force and displacement are downwards .
Hence total work done = - mgh + mgh = 0.
The children will have same kinetic energy as the inclined surface is friction-less so no energy will be dissipated hence addition of energy to boys in both the cases will be same.
The answer is d my friend :)
