# Simple Pendulum period

#### mrnastytime

1. Homework Statement
A pendulum has a period of 1.8 s.

2. Homework Equations
Its length is doubled. What is its period now?

The original pendulum is taken to a planet where g = 16 m/s2.
What is its period on that planet?

3. The Attempt at a Solution
T=2pi sqrt(L/g)
1.8=2pi sqrt(2L/g)

I dont what Im suppose to solve for. This looks like a very simple problem, but i cant seem to figure it out. Maybe i'm over thinking it.

Related Introductory Physics Homework Help News on Phys.org

#### LowlyPion

Homework Helper
1. Homework Statement
A pendulum has a period of 1.8 s.

2. Homework Equations
Its length is doubled. What is its period now?

The original pendulum is taken to a planet where g = 16 m/s2.
What is its period on that planet?

3. The Attempt at a Solution
T=2pi sqrt(L/g)
1.8=2pi sqrt(2L/g)

I dont what Im suppose to solve for. This looks like a very simple problem, but i cant seem to figure it out. Maybe i'm over thinking it.
Well your equations are almost right, but they asked what happens to T when you double L. Presumably 1.8 s is what it is when l = L and they want to know what T is when l = 2L.

#### mrnastytime

What is I?...if the length is doubled, shouldn't the time increase? but how would i interpret that on paper with the given equation?

#### LowlyPion

Homework Helper
What is I?...if the length is doubled, shouldn't the time increase? but how would i interpret that on paper with the given equation?
Not I, little L.

The variable l, in the equation you wrote

T = 2π (g/l)1/2

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving