Unknown Bricks, 1F10.25

Topic and Concept:

Newton's First Law, [:Newtons1STLaw: 1F20. Measuring Inertia]

Location:

Cabinet: [:MechanicsCabinet:Mechanic (ME)]
Bay: [:MechanicsCabinetBayB5:(B5)]
Shelf: #1

attachment:UnknownBricks-01-400.jpg

Abstract:

A lead brick and a wooden block(balsa wood) of the same dimensions are both wrapped in aluminum foil to look identical. Each block is then hit with a hammer. Then toss the wooden block to a student.

Equipment	Location	ID Number

Wrapped Wood and Lead Blocks	ME, Bay B5, Shelf #1
Rubber-Coated Mallet	ME, Bay , Shelf #

Important Setup Notes:

Setup and Procedure:

Place the two blocks on the table, and do not tell the audience which two materials are concealed before their eyes.
Tell the audience you will do your best to apply equivalent forces via the hammer to each block then do it.
Hit the wooden block first (hard) and observe it sliding across the table and onto the floor.
Then hit lead block (with the same force) and observe that it barely moves at all.
Ask the audience what they think the blocks are made of and why one flew across the table well the other didn't move much at all.

Optional:

Don't tell the audience anything.
Hit the lead brick with a b
Act like the wooden block is very heavy and toss it to an audience member to catch.
Toss the light, wood block to a student. If they understand physics well enough, they shouldn't freak out.

Cautions, Warnings, or Safety Concerns:

The lead block is heavy. Don't drop it - it could cause serious damage to the floor, table, or your foot.

Discussion:

The lead block is much more dense than the wood block. Therefore, since the two blocks have the same dimensions, the lead block will be much heavier than the wood block. In other words, the lead block has much more inertia than the wood block. When hitting each block with the hammer, due to the large mass of the lead block, it will barely move and due to the comparatively small mass of the wood block, it will go sliding across the table. These ideas are quantified in Newton's second law: F = m*a, the larger the mass of the object, the less acceleration it will obtain by a given force.

attachment:UnknownBricks-03-250.jpg

attachment:UnknownBricks-09-250.jpg

Videos:

[https://www.youtube.com/user/LectureDemostrations/videos?view=1 Lecture Demonstration's Youtube Channel]

References:

[:Instructional:Home]

-  ⇤ ← Revision 1 as of 2012-07-05 17:57:35 → 
  Size: 1682
  Editor: srnarf
  Comment:
+   ← Revision 6 as of 2012-07-09 16:12:22 → ⇥
  Size: 2967
  Editor: srnarf
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
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-||||[:UnknownBricks:Unknown Bricks]||||
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+Line 7:
-  Newton's First Law, [:Newtons1STLaw#MeasuringInertia: 1F20. Measuring Inertia]
+  Newton's First Law, [:Newtons1STLaw: 1F20. Measuring Inertia]
-Line 16:
+Line 14:
- attachment: mainPhoto
+attachment:UnknownBricks-01-400.jpg
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+Line 18:
-A lead brick and a wooden block(basal wood) of the same size and dimensions are both rapped in aluminum foil to looks the same, are then hit with a hammer. Then toss the wooden block to a student.
+A lead brick and a wooden block(balsa wood) of the same dimensions are both wrapped in aluminum foil to look identical. Each block is then hit with a hammer. Then toss the wooden block to a student.
-Line 24:
+Line 22:
-||apparatus||ME, Bay B1, Shelf #2|| ||
||all other parts||ME, Bay B1, Shelf #2|| ||
||...||ME, Bay B1, Shelf #2|| ||
+||Wrapped Wood and Lead Blocks||ME, Bay B5, Shelf #1|| ||
||Rubber-Coated Mallet||ME, Bay , Shelf #|| ||
-Line 30:
+Line 27:
- *  '''''  '''''
+ *  N/A
-Line 35:
+Line 32:
-. List steps for setup then procedure.
 1. ...
+. Place the two blocks on the table, and do not tell the audience which two materials are concealed before their eyes.
 1. Tell the audience you will do your best to apply equivalent forces via the hammer to each block then do it.
 1. Hit the wooden block first (hard) and observe it sliding across the table and onto the floor.
 1. Then hit lead block (with the same force) and observe that it barely moves at all.
 1. Ask the audience what they think the blocks are made of and why one flew across the table well the other didn't move much at all.

Optional:

 1. Don't tell the audience anything.
 1. Hit the lead brick with a b
 1. Act like the wooden block is very heavy and toss it to an audience member to catch. 
 1. Toss the light, wood block to a student. If they understand physics well enough, they shouldn't freak out.
-Line 39:
+Line 46:
- *
+ * The lead block is heavy. Don't drop it - it could cause serious damage to the floor, table, or your foot.
-Line 44:
+Line 51:
-Discuss the physics behind the demonstration, explaining some of the various steps of the demonstration when appropriate.
+The lead block is much more dense than the wood block. Therefore, since the two blocks have the same dimensions, the lead block will be much heavier than the wood block. In other words, the lead block has much more inertia than the wood block. When hitting each block with the hammer, due to the large mass of the lead block, it will barely move and due to the comparatively small mass of the wood block, it will go sliding across the table. These ideas are quantified in Newton's second law: F = m*a, the larger the mass of the object, the less acceleration it will obtain by a given force.
-Line 46:
+Line 53:
-||attachment: photo||attachment: photo||attachment: photo||attachment: photo||
+||attachment:UnknownBricks-03-250.jpg||attachment:UnknownBricks-09-250.jpg||
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+Line 60:
- * List any references
+ * N/A

fw: Diff for "UnknownBricks"

Unknown Bricks, 1F10.25