Answer:
Explanation:
Velocity of sound in air at 20 degree = 343 m/s
Velocity of sound in water at 20 degree = 1470 m/s
Time taken in to and fro movement in air
=( 2 x 10) / 343 = 0.0583 s
Rest of the time is
.171 - .0583 = .1127 s
This time is taken to cover distance in water. If d be the depth of lake
2d / velocity = time taken
2 d / 1470 = .1127
d = 82.83 m
Answer:
Option (D)
Explanation:
Terrestrial planets refers to those four planets that are nearest to the sun and that lies within the asteroid belt. These planets are mainly composed of rocks or other metal objects that have a hard and resistant surface on it. They have a metal core that is molten (liquid) in nature, and atmosphere is relatively less dense, and also various geological features are present on it like the crater, volcanoes which can be observed with the help of satellites. The average densities of these planets is about four times the density of water. For example, the density of water is 1 g/cm³, whereas the density of earth is 5.5 g/cm³.
Thus, the correct answer is option (D).
This is another time to look at Newton's 2nd law of motion:
Net Force = (mass) x (acceleration)
If the object is not moving, then its acceleration is certainly zero, and Newton's law looks like this:
Net Force = (mass) x (zero)
or Net Force = (zero) .
"Net Force = zero" means that if there ARE any forces acting on the object, then they add up to zero, and we call them "balanced" forces.
So the answer is '<em>yes</em>', and that's why.
Answer:
Explanation:
A grounded wire is sometimes strung along the tops of the towers to provide lightning protection.
In areas where the neutral is grounded or earthed, it is essential to endure that the neutral and the live or hot wires are not confused for each other.
When this happens, the fuses on the transformer will not operate unless the fault is very close to the transformer. The fuses in the consumer's intake box, will not operate.
