# Pendulum Gravity Lab

**Pendulum Gravity Lab**

Purpose: To find the acceleration due to gravity, to introduce students to gravity

Safety: Try not to hit yourself or lab members with pendulum

Hypothesis: What do you think is the rate at which objects accelerate due to gravity on Earth?

Procedure:

1. Attach the pendulum 80 cm length (length is from center of pendulum to where it attaches at the top)

2. Time how long it takes for the pendulum to complete 20 full swings

3. Repeat this 2 more times

4. Record in data table below

5. Divide the Average Time by the amount of swings (20) to find the time of one swing (T), record below

6. Substitute T into the equation below to solve for g

Time (s) / Time (s) / Time (s) / Average Time (s)T = Average Time / 20 swings =

g = 4 ( π 2 ) l / T 2 = 4 ( 3.14 2 ) ( 0.8 ) / ( )2

Observations:

Conclusion: I learned

Questions:

1. What value did you get for g?

2. What is the accepted value for g?

3. What is your percentage error?

Find percentage error by using the following formula

accepted value (9.81m/s2)-your value / accepted value X 100 = %

4. Which of your measurements do you think was the least accurate?

5. Why did you need 20 swings instead of just one?

6. Neglecting air resistance which would hit the ground first a feather or a penny?

7. Define pendulum.

8. What other labs could you use a pendulum for?

9. Which direction does gravity act on objects?

10. Define gravity.

**Pendulum Gravity Lab**

Purpose: To find the acceleration due to gravity, to introduce students to gravity

Safety: Try not to hit yourself or lab members with pendulum

Hypothesis: What do you think is the rate at which objects accelerate due to gravity on Earth?

Procedure:

1. Attach the pendulum 80 cm length (length is from center of pendulum to where it attaches at the top)

2. Time how long it takes for the pendulum to complete 20 full swings

3. Repeat this 2 more times

4. Record in data table below

5. Divide the Average Time by the amount of swings (20) to find the time of one swing (T), record below

6. Substitute T into the equation below to solve for g

Time (s) / Time (s) / Time (s) / Average Time (s)T = Average Time / 20 swings =

g = 4 ( π 2 ) l / T 2 = 4 ( 3.14 2 ) ( 0.8 ) / ( )2

Observations:

Conclusion: I learned

Questions:

1. What value did you get for g?

2. What is the accepted value for g?

3. What is your percentage error?

Find percentage error by using the following formula

accepted value (9.81m/s2)-your value / accepted value X 100 = %

4. Which of your measurements do you think was the least accurate?

5. Why did you need 20 swings instead of just one?

6. Neglecting air resistance which would hit the ground first a feather or a penny?

7. Define pendulum.

8. What other labs could you use a pendulum for?

9. Which direction does gravity act on objects?

10. Define gravity.