Pendulum Period
Presentation
•
Physics
•
11th Grade
•
Hard
Joseph Anderson
FREE Resource
11 Slides • 12 Questions
1
Simple Harmonic
Motion
2
What is Simple Harmonic
Motion?
• Simple Harmonic Motion is motion that
repeats itself on an evenly timed basis.
– The Earth spins around every 24 hours.
– The Earth revolves around the Sun every
365.249 days
– A pendulum swings back and forth
3
What causes Simple Harmonic
Motion?
• Simple Harmonic Motion
(SHM) is caused by a
restoring force.
• A restoring force is a force
that pushes an object back
to its resting state –
equilibrium.
4
Key Words to Know
• Amplitude – how far away from
equilibrium the pendulum is pulled
• Cycle – the complete motion; all the way
until it begins again.
– The same position and direction!!
• Period – how long (TIME!!) it takes for
the pendulum to complete one cycle.
• Frequency – how many times the
pendulum swings back and forth in one
second
5
Why does a pendulum swing back
and forth?
• Gravity! Gravity is the restoring force.
– The pendulum wants to hang straight down.
When we pull it to the side, we are exerting
an applied force.
– When we let go, gravity pulls it back down.
– Because of inertia, the pendulum keeps
swinging till it gets to the other side.
– When it goes as high as it can on the other
side (the same potential energy), gravity
pulls it back.
6
A simple pendulum
A simple pendulum undergoes SHM (simple
harmonic motion) iff all of the following
conditions are met:
1)
The string’s mass is negligible compared to
the bob.
2)
The string doesn’t stretch.
3)
Friction between the string and the support
is negligible.
4)
The initial angle is very small (less than 15o)
7
SHM of a Pendulum
•
8
Implications
As the length of the pendulum increases,
the period increases. Does this make
sense?
As the length increases, the bob has to
travel farther in order to complete the
cycle. Therefore, it should take longer!
As for the frequency, since the pendulum has
longer to go, it can complete fewer cycles,
and so the frequency decreases.
9
Example
• What is the period on Earth of a
pendulum that is 2m long?
• What is the period of that same
pendulum on the moon, where gravity is
1.6m/s2?
10
Solution
• What is the period on Earth of a
pendulum that is 2m long?
11
Example
What is the period of that same
pendulum on the moon, where gravity is
1.6m/s2?
12
Multiple Choice
If the length of a pendulum increases, its period....
increases
decreases
stays the same
13
Multiple Choice
The restoring force on a pendulum is
increasing
gravity
electrical
friction
14
Multiple Choice
If a pendulum is moved to a planet and its period increases, the gravity on that planet is ___________ the gravity on Earth.
the same as
less than
greater than
can't tell; period doesn't depend on gravity
15
Multiple Select
Which of the following are most likely to result in simple harmonic motion? Select two answers.
A hole is drilled through one end of a meter stick, which is hung vertically from a frictionless axle. The bottom of the meter stick is displaced 12 degrees and released.
A hole is drilled through one end of a meter stick, which is hung vertically from a rough axle. The bottom of the meter stick is displaced 12 degrees and released. Every time the meter stick swings back and forth the axle squeaks.
A block is hung vertically from a linear spring. The opposite end of the spring is attached to a stationary point. The entire apparatus is placed in deep space. The block is displaced 4 cm from equilibrium and released.
A block is placed on a frictionless surface and attached to a non-linear spring. The opposite end of the spring is attached to a wall. The block is displaced 2 cm from equilibrium and released.
16
Multiple Choice
Student X attaches an object of mass M to the end of a string of length L so that a simple pendulum is constructed. Student Y attaches an object of mass M to a string of length 4L to construct a second pendulum.
Which of the following claims correctly compares the periods of both pendula?
The period of Student X’s pendulum is the same as the period of Student Y’s pendulum.
The period of Student X’s pendulum is four times the period of Student Y’s pendulum.
The period of Student X’s pendulum is twice the period of Student Y’s pendulum.
The period of Student X’s pendulum is half the period of Student Y’s pendulum.
17
Multiple Choice
The gravitational field strength near Jupiter’s surface is nearly 2.53 times greater than the gravitational field strength near Earth's surface. Which of the following claims is correct about the period of a pendulum if it oscillates near Jupiter’s surface and near Earth’s surface?
The period of the pendulum will be greater on Jupiter.
The period of the pendulum will be greater on Earth.
The period of the pendulum is the same on both planets.
A comparison of the period of the pendulum for both planets cannot be made without more information about the length of the pendulum.
18
Multiple Choice
period.
frequency.
vibration.
amplitude.
19
Multiple Choice
amplitude
period
frequency
revolution
20
Multiple Choice
amplitude
period
frequency
revolution
21
Multiple Choice
Increase
Decrease
Stays the same
Need more information
22
Multiple Choice
Increase
Decrease
Stays the same
Need more information
23
Fill in the Blanks
Type answer...
Simple Harmonic
Motion
Show answer
Auto Play
Slide 1 / 23
SLIDE
Similar Resources on Wayground
16 questions
Motion, Distance and Displacement
Presentation
•
11th Grade
17 questions
Civics Prep
Presentation
•
11th Grade
20 questions
Vertical and Horizontal Asymptotes
Presentation
•
11th Grade
16 questions
Civil Rights Landmarks
Presentation
•
11th Grade
18 questions
Pengukuran
Presentation
•
10th Grade
19 questions
Principles of Geology
Presentation
•
11th Grade
19 questions
Radioactive Decay
Presentation
•
10th Grade
Popular Resources on Wayground
24 questions
PBIS-HGMS Day 10
Quiz
•
6th - 8th Grade
10 questions
HCS SCI 03 Summer School Review 3
Quiz
•
3rd Grade
11 questions
Home Scope
Quiz
•
7th - 8th Grade
15 questions
HCS SCI 05 Summer School Assessment 3 Review
Quiz
•
5th Grade
35 questions
Lufkin Road Middle School Student Handbook & Policies Assessment
Quiz
•
7th Grade
18 questions
Geo 11.3 Area of Circles and Sectors
Quiz
•
9th - 11th Grade