# Homework Help: Pendulum type questions

1. Apr 28, 2010

### IB1

1. The problem statement, all variables and given/known data

1. A long pendulum has time period 10s. If the bob is displaced 2m from the equilibrum position and released, how long will it take to move 1m ?

2. As a mass on a spring travels upwards through the equilibrium position, its velocity is 0.5m/s. If the frequency of the pendulum is 1Hz what will be the velocity of the bob after 0.5s ?

2. Relevant equations

$$v=-v_{o}\sin{\omega t}$$
$$x=x_{o}\cos{\omega t}$$

3. The attempt at a solution

I've tried to use the formulas above, but it didn't work for me. These questions are supposed to be easy.

2. Apr 29, 2010

### Redbelly98

Staff Emeritus
For #1, use your equation x=x0cos(ωt).
Just plug in the values for x, x0, and ω. Then solve it for t.
(You will need to figure out the value of ω first.)