Question

\int { mg\cos { \theta } d\theta } =\int { mR\ddot { \theta } } d\theta

Answer 1

\[\int\limits { mg\cos { \theta } d\theta } =\int\limits { mR\ddot { \theta } } d\theta \]

Answer 2

integrate wrt theta ,theta dot and theta double dot. i will give medal .can aby body help.

Answer 3

What math is this? This looks really hard.

Answer 4

integration @asdfasdf54514

Answer 5

@satellite73

Answer 6

\[\int mg \cos \theta d\theta\]
mg are constant with respect to theta, bring them out
\[mg\int \cos \theta d\theta\]
can you integrate it now? @CGGURUMANJUNATH

Answer 7

my question is can u integtate lhs and rhs wrt theta ? @ash2326

Answer 8

is it the original question ?

Answer 9

s

Answer 10

yes, you can do that

Answer 11

can u show me the steps or draw which ever is convenient to u @ash2326

Answer 12

the m's will cancel

Answer 13

\[\int\limits { mg\cos { \theta } d\theta } =\int\limits { mR\ddot { \theta } } d\theta\]
\[mg\int \cos \theta d\theta=mR\int \ddot \theta d\theta\]
We know that
\[\frac{d}{d\theta} \dot \theta=\ddot \theta\]
so
\[mg\int \cos \theta d\theta=mR\dot \theta +C\]
where C is constant, I think you can integrate the left side, can't you?

Answer 14

the dots are wrt to t or theta ?!

Answer 15

usually dots mean derivative with respect to time

Answer 16

ok @ash2326 u have integrated wrt theta right ?

Answer 17

can u integrate wrt theta dot.

Answer 18

yes, cause we have dtheta in the equation. No info about time

Answer 19

no

Answer 20

no information is given wrt time.

Answer 21

@CGGURUMANJUNATH are the dots mean derivative with respect to theta or with respect to time ?

Answer 22

theta @Coolsector

Answer 23

ok.

Answer 24

can u show me the steps plz @Coolsector

Answer 25

what steps ? if you say that the dots are with respect to theta then see the solution ash gave you

Answer 26

ok what ash has done wrt theta is fine ,can u integrate wrt theta dot.

Answer 27

@Coolsector

Answer 28

theta dot =\dot { \theta }

Answer 29

\[\dot { \theta } \]

Answer 30

i meant.

Answer 31

my question is can u integtate lhs wrt theta and rhs wrt theta dot ;is it possible to do that ?

Answer 32

you mean
in case your original equation:
mgcos(theta) = mR* (theta double dot )
?

Answer 33

if so you cant integrate like this one side wrt to one varible and the other wrt to another

Answer 34

thank you very much @Coolsector @ash2326 and @UnkleRhaukus

Answer 35

anyway. i still cant get it.
if dot means derivative with respect to theta
then theta dot should be 1.

Answer 36

it is like taking the derivative of x wrt to x.
and the second derivative would be 0.

Answer 37

it is like taking the derivative of x wrt to x.YES IT IS RIGHT,
then theta dot should be 1. HOW @coolsector.

Answer 38

@Coolsector @ash2326 @UnkleRhaukus chech out the attachment.

Answer 39

sorry check not chech this was the actual problem .

Answer 40

well the derivative shold be with respect to time as @Coolsector sugessted.

Answer 41

ok.