Category Archives: Properties of Matter

Young’s Modulus

Demo: ME-R-YM
Pira Index: 1R 20.15

 Lab Equipment  Directions
  1.  tall lab stand
  2. expansion scale with clamp and pointer
  3. hook clamp
  4. iron wire – 28 gauge
  5. parallel clamp
  6. pulley
  7. two small blocks of wood
  8. two 90 degree clamps
  9. five 1kg slotted masses
  10. large weight hanger
  11. goggles
  1.  Set up as shown with lab stand extending over cart (pulley end should not be extended much).
  2. Attach one end of wire securely to hook clamp, run it over scale pointer and pulley, and attach far end of wire to weight hanger.
  3. Add masses on weight hanger noting amount of stretch in wire.
  4. If you continue adding mass until elastic limit is passed, wire stretches beyond its limit of return.
Caution: The wire may break. Protect your eyes and toes.


Happy-Sad Balls

Demo: ME-R-HS
Pira Index: 1R 40.30

 Lab Equipment  Directions
  1.  happy-sad balls
  1.  Show that the balls appear to be identical in size, weight, and appearance.
  2. Simultaneously drop the balls from the same height.
  3. Observe that one ball bounces and the other one does not. Why?


Hooke’s Law II

Demo: ME-R-HO
Pira Index: 1R 10.00

 Lab Equipment  Directions
  1.  lab stand
  2. two 90 degree clamps
  3. two cross bars
  4. set of five Hooke’s law springs with labels indicating ‘k’ values
  5. paper showing ‘k’ ratios
  6. hooked masses: 2-10g, 3-20g, 1-50g, and 1-100g
  1.  Set up as shown. Slide paper of ‘k’ ratios over lower bar. Slide the movable pointers of each spring so all line up with the top of the paper.
  2. Position masses below the spring as follows: 1 – 10g k spring, 2 – 20g k spring, 4 – 40g k spring, 6 – 60g k spring, 10 – 100g k spring
  3. After pointing out that all pointers are aligned with no masses on the springs, add the masses to each spring.
  4. Re-position the bar with the k ratio paper down to show pointers are still in line.


Hooke’s Law Demo

Demo: ME-R-HL
Pira Index: 1R 10.00

 Lab Equipment  Directions
  1.  five springs
  2. five 500 gram hooked masses
  3. crossbar
  4. lab pole
  5. 90 degree clamp
  6. telescope clamp
  7. wood block
  1.  Set up experiment as shown.
  2. Note the displacement that occurs when equal masses are hung from each spring.
  3. Start oscillating each spring.
  4. Also note the different spring constants.