Question

a pendulum of mass m and length L is pulled back an angle θ and released. After the pendulum swings through its lowest point, it encounters a peg α degrees out and r meters from the top of the string. The mass swings up about the peg until the string becomes slack with the mass falling inward and hitting the peg. show that cosθ=r/Lcosα-√3/2(1-r/L)

Answer 1

I tried to find the forces on the pendulum at the initial and final position
Lcosθ-mg=0
Lsinθ=ma
rcosθ-mg=0
rsinθ=ma
but it doesn't seem to work at all. what I get is that r=L which is impossible. :(

Answer 2

noyhing

Answer 3

pellet man i am stuck....!!

Answer 4

pellet man

Answer 5

pellet means what

Answer 6

Dude how can i get it solved?

Answer 7

one minute i am thinking solution

Answer 8

hey aryan are you listening

Answer 9

yeah i am here...

Answer 10

see take cos and tan make them negative of pendulum opposite position and make it positive and you will find your answer ok got it so easy

Answer 11

ok got it aryan

Answer 12

ok i will try..if i am stuck i will get back to you.

Answer 13

ok np