Density Of A Coin Lab 2r624o

EXPERIMENT: Mechanics

AIM: To determine the density of a 1 cent coin.

THEORY: The density of a substance is the ratio of the mass to the volume of the substance. Density In other is mass per unit volume. Therefore the formula for density can be found using the formula: Density (ρ) = Mass/ Volume. Density. If the density of an object is less than the density of the liquid it is placed in, the object will float. However if the density of the object is greater than that of the liquid it will wink.

VARIABLES: Controlled- Coin, Displacement Can, Amount of paper clips used for each part of the experiment (Amount placed on the triple beam balanced must be equal to the number placed in the displacement can), Manipulated: Water Responding- Weight and Volume, Density

APPARATUS: Displacement Can 100 One Cent Coins 100cm3 Measuring Cylinder. Water Triple Beam Balance

METHOD: 1. A 100 paper clips were place on the triple beam balance to obtain its weight 2. The total weight obtained was then divided by 100 to obtain the reading of one paper clip 3. A displacement can was then filled with water and was allowed to drain all the excess water completely. 4. A measuring cylinder was then placed at the bottom of the displacement can and the 100 paper clips were placed into the can. 5. The water was allowed to drip completely into the measuring cylinder. 6. After all the water was allowed to drip out, the reading of the measuring cylinder was taken and divided by 100. Diagram Coins

Readi ngs

Pointe r

DIAGRAM SHOWING METHOD OF FINDING THE VOLUME OF 100 COINS BEING USING A DISPALEACMENT CAN.

Water Dripping Into Measuring Cylinder Displacement Can 100 cm3 Measuring Cylinder 100 coins

The Volume Of 100 Paper Clips After All Water Has Been Dripped

Table Stands

RESULTS: TABLE SHOWING THE DENSITY AND THE DENSITY OF A 1 CENT COIN

Mass/g

100

Volume/c m3 23

194.6

Density g/cm3 8.46

1

0.23

1.946

8.46

No. of 1Cent coins

CALCULATIONS: Volume of 100 1cent coins = 23 Volume of 1 1cent coin = 23/100 =0.23 cm3

Mass of 100 1cent coins = 194.6 Mass of 1 1cent coin = 194.6/100 = 1.946 g

Density of 1 one cent coin = Mass/Volume = 1.946 g/0.23 cm3 = 8.46 g/cm3

PRECAUTIONS: 1. The 1 cent coins were placed on the centre of the triple beam balance to obtain a more accurate reading 2. All the water was ensured to have drained out completely from the displacement can before placing the coins. 3. The coins were placed into the displacement can gently to ensure that the water didn’t splash or caused any waves that will push more water out of the can 4. All fans were switch off and windows were closed to help prevent excessive wind from blowing the water. 5. Instruments were ensured that there were no systematic errors.

6. When reading the measuring cylinder, It was ensured that it was resting on a flat surface 7. The bottom of the meniscus was read and parallax error was avoided.

SOURCES OF ERROR: 1. Environmental wind was present which would have slightly bowed the water. 2. All the water molecules wouldn’t have drained out completely. Some would have slicked onto the spout. 3. The can was slightly vibrated due to shaking of the surface. 4. Due to insufficient time, the displacement can was not allowed to fully settle out 100%.

DISCUSSION: The relative density was obtained using the formula Density = Mass/ Volume. After conducting the experiment the mass and volume of one coin was 1.946 g and 8.46 cm 3 respectively. After obtaining the results the density was then further calculated and found to be 8.46 g/cm3. From there, the relative density can also be calculated using the formula Relative density (Pr) = Density of the substance (Ps)/ Density of water (Pw). Knowing that the density of water is 1gcm-3, the relative density of one coin is 8.46. Since a 1 cent coin has a higher density than water, if placed in water the paper clip will sink. Also, oil, having a lower density than water, floats on water. This thus means that oil has a lower density than 1gcm -3 therefore if a one cent coin was placed in oil, the coin would be expected to sink. This experiment was successful but could have been improved. Using a sensitive digital scale would have been more precise than the analogue triple beam balance. This experiment could have also been conducted twice then the average could have been found to obtain a more accurate result or to ensure that it was done correctly the first time. After conducting this experiment it was realized that this experiment was one of the least enjoyable ones.

CONCLUSION: Within the limits of experimental error, the density of a 1cent coin was determined to be 8.46 g/cm3.