# A pendulum 45cm long swings through a vertical angle of 30 degrees.Find the height through which the pendulum bob rises. Can you solve it using numerical trigonometry as I am currently learning...

A pendulum 45cm long swings through a vertical angle of 30 degrees.Find the height through which the pendulum bob rises.

Can you solve it using numerical trigonometry as I am currently learning about it.Thanks

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Expert Answers

crmhaske | Certified Educator

Step 1: Solve for x, which is the length of the line between the ceiling and the point where the imaginary line from the pendulum bob meets the wall.

`cos30=(adj.)/(hyp.)=x/45-gtx=45cos30~~39`

Step 2: Solve for h, which is equal to the length of the pendulum minus` ` x:

`h=45-x=45-39=6`

Therefore, the pendulum bob has risen 6cm.

See image.

Further Reading:

crmhaske | Certified Educator

See image.