# Mechanics (Pendulum) Question (1 Viewer)

#### mrbunton

##### Member
b)
(dividing the 2 equations from part a)

(from triangle formed by pendulum)

remove r at bottom and divide by R to get answer

c)
cos a is between a certain region; where it is equal or less than 1 or greater or equal to min value of cosa which occurs when a is max;

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#### altSwift

##### Member
b)
(dividing the 2 equations from part a)

(from triangle formed by pendulum)

remove r at bottom and divide by R to get answer

c)
cos a is between a certain region; where it is equal or less than 1 or greater or equal to min value of cosa which occurs when a is max;

why is the lower bound? thanks

#### mrbunton

##### Member
when a is max; cosa is minimum. a is max when it is right on the edge of the bowl; so height of ball is h; we take R-h to find the adjacent side of the triangle. hence R-h/R is equal to cosa at its minimum value

Last edited:

#### altSwift

##### Member
when a is max; cosa is minimum. a is max when it is right on the edge of the bowl; so height of ball is h; we take R-h to find the adjacent side of the triangle. hence R-h/R is equal to cosa at its minimum value
rip, i completely missed that the vertical length is R as well. thanks again!