Because some scientific theories are true and some are false
D. It happens all the time
Answer:
Option d is correct.
Explanation:
We know , resistance of a body is directly proportional to its length and inversely proportional to its area.
( Here, 
is constant dependent on object material )
Writing 
also :
( since they are of same material therefore, is same.)
Now , if 
.
Then 
Therefore, option d. is correct.
Hence, this is the required solution.
Planets orbit the sun in the paths which are known as elliptical orbit. Each planet has its own orbit around the sun and direction in which all the planets orbit around the sun are the same. These orbits were well explained by the astronomer Kepler. The gravity of the Sun keeps the planets in their orbits. They stay in their orbits because there is no other force in the Solar System which can stop them.
Answer:
As with any wave the speed of sound depends on the medium in which it is propagating.
Explanation:
