Question

What is degree of freedom? How many degrees of freedom does a cricket ball hit by a batsman has?

Answer 1

translational degree 1
rotational degree 3
vibrational degree 0
total degrees of freedom 4

Answer 2

How do you get those number of degrees of freedom?

Answer 3

as its name suggests no of ways in which a body can freely involve in different types of motion

Answer 4

But my book says its two in case of cricket ball (in air) hit by a a batsman since it is free to move in vertical and horizontal planes only!

I just don't get this "degree of freedom" thing!

Answer 5

Haha ujjwal, the book is exactly right, it's looking at the components of a projectile, in this case horizontal and vertical elements.

Answer 6

I got that after i saw the answer! But i want to get core concepts of degree of freedom!

Answer 7

Are you familiar with the term "vector"?

Answer 8

yes!

Answer 9

"Degrees of freedom" is the dimension of the domain of a random vector, or essentially the number of "free" components, that is, how many components need to be known before the vector is fully determined. Essentially degrees of freedom refers to how many vectors you need to fully express the motion of something.

Answer 10

Ok, Now since the ball is in space with three spatial dimensions, shouldn't the degree of freedom be three?

Answer 11

Yes, I could see how you would think that, but I believe it lies in the fact that whichever direction it travels in becomes the designated axis, so then you only actually need two vectors to define it. I'm trying to think of an easy way to put it xD

Answer 12

"The number of independent ways in which a mechanical system can move without violating constraint which may be imposed is called a number of degree's of freedom"

Answer 13

A cricket ball is a rigid body .... you need three coordinates to specify the CM of ball ... and other three coordinates for orientation of it. So if you treat cricket ball as system of particles, then it has six degree's of freedom.

Answer 14

if there are certain constraints imposed on the ball ... then the no of constraints reduce the degree of freedom.

Answer 15

So, "A cricket ball hit by a batsman for a six" (that is mentioned in question) has six degrees of freedom?

Answer 16

if you consider cricket to be rigid body ... and (the ball is not already hit by bats man)

Answer 17

after hit ... the ball is constrained to move in one plane section (if you neglect air resistance). you can specify the position of CM of ball ... by two coordinates. distance and height.

Answer 18

I guess i get it to some extent but this one is totally new for me..

Answer 19

classical mechanics ... http://mitpress.mit.edu/sicm/book-Z-H-4.html

Answer 20

Do i need to go through all of them to understand degree of freedom? I guess no..
And even i don't like reading bulk..
I tried searching on youtube but didn't find anything good!

Answer 21

Wow! That's a lot for today! And i am a beginner.. So, they will ask me questions appropriate for a beginner!

Answer 22

Thanks @demitris !