Differences between revisions 1 and 25 (spanning 24 versions)

Balls and Plate, 4A30.22

Topic and Concept:

Thermal Properties of Matter, 4A30. Solid Expansion

Location:

Cabinet: Thermodynamics (TD)
Bay: (A3)?
Shelf: #1?

Abstract:

A plate with a hole is heated with a set of two balls, one over and one under size. Heat the plate and slip over both.

Equipment	Location	ID Number
A brass plate with a hole	TD, A3, Shelf #1	4A30.22
Two metal balls attached to a rod	TD, A3, Shelf #1	4A30.22
Burner	location	NA
Liquid Nitrogen	location	NA
Safety glove and glasses	location	NA
Red and white gas carts	Rooms 2103, 2241, (and 2223 upon request)

Important Setup Notes:

This demonstration requires a supply of methane gas usually provided by the red and white gas carts found in rooms 2103, 2241, (and 2223 upon request).
This demonstration requires a supply of liquid nitrogen. The main supply is located at the loading dock. If 12 hours notice given to lecture demo, supply will be provided.

Setup and Procedure:

To light the burner, connect the attached gas hose to the gas out (red panel) on the red and white gas cart.
Open the gas valve.
Light a match and bring it near the top of the burner.
The flame will ignite the gas. Adjust the flame height accordingly by adjusting the valve.

Option A. Shrinking and expanding the balls

Show that the smaller ball can get through the hole and the larger ball cannot.
Heat the smaller ball with the burner and show that the smaller ball can no longer fit through the hole.
Soak the larger ball in the liquid nitrogen and show that the larger ball can now fit through the hole.

Option B. Expanding the hole

Demonstrate to students that the smaller ball can get through the hole and the larger ball cannot.
Place the burner beneath the plate to heat it.
Show that both balls now fit through the hole.

Cautions, Warnings, or Safety Concerns:

Always use the gloves and safety glasses throughout this demonstration.
Beware of the heated plate - contact with skin could cause severe burns!
Use care when working with the liquid nitrogen - prolonged contact with skin causes severe frostbite!

Discussion:

When the plate is heated, the dimensions of the plate increase while maintaining their relative proportions. In other words, the overall area of the plate expands along with the size of the hole while the ratio of hole area to plate area remains the same. Heating causes the molecular bonds to lengthen, which causes the material to expand. You can think about it this way: a group of people standing in a tight circle with elbows linked try to lengthen their "bonds" by moving to hold hands at arms length. They have to expand the circle by standing back everyone stands further apart. This is analogous to the molecular bonds around the hole. This is considered a 2D expansion (the plate thickness is quite thin relative to the other dimensions) and can be described by

ΔA/A = α_A*ΔT = α_L²*ΔT

where A is the area at temperature T_i, ΔA is the change in area when the material is at temperature T_f, ΔT is T_f - T_i, and α is the coefficient of thermal expansion which depends on the material. See references below for more information.

Videos:

Lecture Demonstration's Youtube Channel

References:

Home

-  ⇤ ← Revision 1 as of 2009-09-23 16:30:08 → 
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+   ← Revision 25 as of 2013-07-17 17:22:18 → ⇥
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-=  Balls and Plate , 4A30.21 =
+||<30%  style="text-align:center">[[PiraScheme#Thermodynamics|Table of Thermodynamics Demonstration]] ||<30%  style="text-align:center">[[TDEquipmentList|Thermodynamics Equipment List]] ||<30%  style="text-align:center">[[Demonstrations|Lecture Demonstrations]] ||


= Balls and Plate, 4A30.22 =
'''Topic and Concept:'''

 . Thermal Properties of Matter, [[ThermalProperties#SolidExpansion|4A30. Solid Expansion]]
-Line 5:
+Line 11:
- * '''Cabinet:''' Thermodynamics Cabinet 
 * '''Bay:''' (A3)
 * '''Shelf:''' #1
-Line 9:
+Line 12:
-(attachment photo showing the fully set up demonstration)
+ * '''Cabinet:''' [[ThermoCabinet|Thermodynamics (TD)]]
 * '''Bay:''' [[ThermoCabinetBayA3|(A3)]]?
 * '''Shelf:''' #1?
-Line 11:
+Line 16:
-'''Description:'''
+{{attachment:4A30-22_01.jpg}}
-Line 13:
+Line 18:
-Insert description of apparatus, its component, what it is demonstrating.
+'''Abstract:'''
-Line 15:
+Line 20:
-||<:style="width: 60%" :40%>'''Equipment'''||<:30%>'''Location'''||<:25%>'''ID Number'''||
|| || || ||
||apparatus||ME, Bay B1, Shelf #2|| ||
||all other parts||ME, Bay B1, Shelf #2|| ||
||...||ME, Bay B1, Shelf #2|| ||
||Possible supplies that are needed||Rode and Tack Cabinet|| ||
||...|| In Lecture Halls|| ||
||...|| Stock Cabinet || ||
||...|| Stock Cabinet || ||
+A plate with a hole is heated with a set of two balls, one over and one under size. Heat the plate and slip over both.
||<40%  style="text-align:center">'''Equipment''' ||<30%  style="text-align:center">'''Location''' ||<25%  style="text-align:center">'''ID Number''' || || || || ||
||A brass plate with a hole ||[[ThermoCabinetBayA3|TD, A3, Shelf #1]] ||<style="text-align:center">4A30.22 ||
||Two metal balls attached to a rod ||[[ThermoCabinetBayA3|TD, A3, Shelf #1]] ||<style="text-align:center">4A30.22 ||
||Burner ||location ||<style="text-align:center">NA ||
||Liquid Nitrogen ||location ||<style="text-align:center">NA ||
||Safety glove and glasses ||location ||<style="text-align:center">NA ||
||[[RedWhiteGasCart|Red and white gas carts]] ||Rooms 2103, 2241, (and 2223 upon request) || ||
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+Line 29:
-'''Setup:'''
-Line 27:
+Line 30:
-. Make a Setup check list.
 1. ...
+'''''Important Setup Notes:'''''

 * This demonstration requires a supply of methane gas usually provided by the [[RedWhiteGasCart|red and white gas carts]] found in rooms 2103, 2241, (and 2223 upon request).
 * This demonstration requires a supply of liquid nitrogen. The main supply is located at the loading dock. If 12 hours notice given to lecture demo, supply will be provided.

'''Setup and Procedure:'''

 1. To light the burner, connect the attached gas hose to the gas out (red panel) on the [[RedWhiteGasCart|red and white gas cart]].
 1. Open the gas valve.
 1. Light a match and bring it near the top of the burner.
 1. The flame will ignite the gas. Adjust the flame height accordingly by adjusting the valve.

Option A. Shrinking and expanding the balls

 1. Show that the smaller ball can get through the hole and the larger ball cannot.
 1. Heat the smaller ball with the burner and show that the smaller ball can no longer fit through the hole.
 1. Soak the larger ball in the liquid nitrogen and show that the larger ball can now fit through the hole.

Option B. Expanding the hole

 1. Demonstrate to students that the smaller ball can get through the hole and the larger ball cannot.
 1. Place the burner beneath the plate to heat it.
 1. Show that both balls now fit through the hole.
-Line 31:
+Line 57:
-. List any Warnings....
 1. Demonstration may require practice.
+ * Always use the gloves and safety glasses throughout this demonstration.
 * Beware of the heated plate - contact with skin could cause severe burns!
 * Use care when working with the liquid nitrogen - prolonged contact with skin causes severe frostbite!

'''Discussion:'''

When the plate is heated, the dimensions of the plate increase while maintaining their relative proportions. In other words, the overall area of the plate expands along with the size of the hole while the ratio of hole area to plate area remains the same. Heating causes the molecular bonds to lengthen, which causes the material to expand. You can think about it this way: a group of people standing in a tight circle with elbows linked try to lengthen their "bonds" by moving to hold hands at arms length. They have to expand the circle by standing back everyone stands further apart. This is analogous to the molecular bonds around the hole. This is considered a 2D expansion (the plate thickness is quite thin relative to the other dimensions) and can be described by

ΔA/A = α,,A,,*ΔT = α,,L,,^2^*ΔT 

where A is the area at temperature T,,i,,, ΔA  is the change in area when the material is at temperature T,,f,,, ΔT is T,,f,, - T,,i,,, and α is the coefficient of thermal expansion which depends on the material.  See references below for more information.

|| {{attachment:4A30-22_01a.jpg}} || {{attachment:4A30-22_02a.jpg}} || {{attachment:BallsPlate03-250.jpg}} || {{attachment:BallsPlate04-250.jpg}} ||
|| {{attachment:BallsPlate05-250.jpg}} || {{attachment:BallsPlate06-250.jpg}} || {{attachment:BallsPlate07-250.jpg}} ||
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+Line 74:
-'''Demonstration:'''
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+Line 75:
-Insert description of demonstration, how is the demonstration preformed.
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+Line 76:
-||attachment other photos||attachment other photos||
||attachment other photos||attachment other photos||
+'''Videos:'''

 * [[https://www.youtube.com/user/LectureDemostrations/videos?view=1|Lecture Demonstration's Youtube Channel]]
-Line 44:
+Line 82:
-. List any references
+ * [[https://en.wikipedia.org/wiki/Thermal_expansion|Wikipedia - Thermal Expansion]]
 * [[http://en.wikipedia.org/wiki/Coefficient_of_thermal_expansion|Wikipedia - Coefficient of Thermal Expansion]]
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+Line 85:
-[Insert a back link to main topic list] 

[:Demonstrations:Demonstrations]

[:Instructional:Home]
+[[Instructional|Home]]

fw: Diff for "BallsPlate"

Balls and Plate, 4A30.22