•THAT THE PROPAGATION OF SOUND WAVES NEED MEDIUM TO TRAVEL
•THE MEDIUM SHOULD POSSES ELASTICITY
•FOR THE FASTER PROPAGATION OF SOUND THE PARTICLES SHOULD BE VERY CLOSE TO EACH OTHER
Answer:
a.
Explanation:
The air moves faster across the top of the surface and exerts less pressure on the air below and thus due to difference in air pressure the top roof is lifted.
hence the correct option is pressure underneath them is reduced.
Answer:

Explanation:
As we know that the sixth order maximum will have path difference given as

here we know that
N = order of maximum

now we have

so we know that


Answer:
The force required will be "300 N".
Explanation:
The given values are:
Mass of object,
m = 300 kg
Acceleration,
a = 1 m/s
Now,
The force will be:
⇒ 
On substituting the values, we get
⇒ 
⇒ 