Homework Help

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

user profile pic

phanpal999 | Student, Grade 8 | Salutatorian

Posted May 19, 2013 at 1:07 AM via web

dislike 0 like

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

1 Answer | Add Yours

user profile pic

crmhaske | College Teacher | (Level 3) Associate Educator

Posted May 19, 2013 at 1:25 AM (Answer #1)

dislike 1 like

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.

Sources:

1 Reply | Hide Replies

Top Answer

user profile pic

crmhaske | College Teacher | (Level 3) Associate Educator

Posted May 19, 2013 at 1:25 AM (Reply #1)

dislike 1 like

See image.

Images:
This image has been Flagged as inappropriate Click to unflag
Image (1 of 1)

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes