Explanation:
For example, when a drum is struck, the flexible skin (sometimes called a membrane) of the drum vibrates. The compression and expansion of the air on either side of the vibrating membrane produces differences in air pressure. The pressure differences generate a sound wave that propagates outward from the drum surface.
Answer:
Explanation:
In case of diffraction , angular width of central maxima =2 λ/d
λ is wave length of light and d is slit width
In case of interference , angular width of each fringe
= λ /D
D is distance between two slits
No of interference fringe in central diffraction fringe
=2 λ/d x D/λ = 2 x D /d = 2 x .24/.03 = 16.
Answer:

Explanation:
As we know that average velocity is defined as the ratio of total displacement of the object and its time interval.
so here we can say

now we know that in one complete revolution the total displacement of the tip of the seconds hand is zero
because it will have same position after one complete revolution from where it starts
so here we can say that the average velocity will be zero

Answer:
Toward the centre of the circular path
Explanation:
The can is moved in a circular path: this means that it is moving by circular motion (uniform circular motion if its tangential speed is constant).
In order to keep a circular motion, an object must have a force that pushes it towards the centre of the circular trajectory: this force is called centripetal force, and its magnitude is given by

where m is the mass of the object, v its tangential speed, r the radius of the trajectory. This force always points towards the centre of the circular path.