# Trig word problem

## Homework Statement

A pedulum, which is 0.5 m long, swings back and forth. The angle of it's displacement from it's original position is modelled by:
Theta = 1/4Sin(Pi/3)

IN the first 4 seconds, when will the vertical displacement of the pendulum be 1 cm?

## The Attempt at a Solution

What I did was:
Find the angle theta.
The pendulum can swing to the left into an imaginary "Quadrant 3" so
sin theta = 0.01/0.5
theta = _____

Then I subbed that into the equation and got a decimal answer.
I was sure there was more than one answer, so in the last minute, I added Pi and _____, since it's in the third quadrant. And ended up with 3. something.

The other class did this question the day before our test and ended up with 4 answers!
I looked at the solutions, but one of them was 5.94 or along those lines, but it didn't satisfy what the question was looking for - the first 4 seconds
That teacher also drew the 1 cm displacement on the horizontal component of the pendulum, which was odd... didn't it ask for the vertical?

?
:(

Related Precalculus Mathematics Homework Help News on Phys.org