1. What was the mass of displaced water and magnitude of the buoyant force on your empty plastic box? Did these values agree with the mass and weight of your box? Explain why or why not.(A correct answer to this question will include the estimated uncertainties of your results. See the statement about measurement uncertainties included with the data.)

2. What was the maximum number of dimes you could add to your box before it sunk? With the maximum number of dimes added, to what depth did your block float and what percentage of your box was underwater?

3. What was the density of your billiard ball? Which of the three types of material do you believe it was made from and why? (Once again, a correct answer to this question will include discussion of the uncertainty of your results.)

use this data for the part below

d(m). L(m). m(kg). h(initial)(m). h(final)(m). m_a(kg) m_w(kg)

.075. .038. .031. .12 .127 .124 .056

1. EMPTY PLASTIC BOX

The plastic box will float inside a cylindrical beaker full of water. The box is hollow and has a watertight removable lid. Initially it will be empty and you will compare the mass of the box and the buoyant force from the water it floats in. 1.1 MEASURING THE BEAKER

Measure the diameter (d) of the cylindrical plastic beaker and calculate the area of its (circular) base using A = pr2. (

You will do a lot of calculations in this lab. Be sure to label your Excel file well, so your TA can easily find your results for the many calculations you do. Remember to include all the equations you use in your Excel file.

1.2 DIMENSIONS OF BOX

Measure the side length (L) and mass (m) of the plastic box and calculate its volume, weight and density. (You will use the weight below, and the density in section 2.)

1.3 VOLUME OF DISPLACED WATER

Before adding the box, measure the water level in the beaker (hi) as a height above the base.Add the box to the beaker and wait until is floating without bobbing up and down. (The boxes used in this lab always float level as shown in the picture at the end of the theory.) Measure the water level in the beaker with the box floating in it (hf). The water displaced by the box is the height change

experiment are included with the data.) (hf - hi) multiplied by the base area of the beaker. Calculate the volume of the water displaced by

the box.

1.4 MASS OF DISPLACED WATER

Using the volume of water and Equation 1 (from the theory), calculate the mass of the displaced water and the buoyant force on the box. (Youll be discussing your result in your report.)

2. BOX CONTAINING DIMES

The box is now weighed with as many dimes as possible before it starts sinking.

2.1 CALCULATE MAXIMUM MASS

If the box were completely submerged the buoyancy force would increase since the box would be displacing more water. Using the volume of your box and the density of water calculate the mass of water displaced by a fully submerged box. 2.2 CALCULATE ADDITIONAL MASS

The difference between the (maximum) mass of water displaced and the mass of your box is the additional weight that the box could support before sinking. In kilograms, calculate how much additional mass your box could support before sinking. (Sinking means the buoyancy force exceeds the weight of the box.)

2.3 FLOATING WITH DIMES

The mass of a US dime is 2.268 grams. Calculate the maximum number of dimes you could add to the box so that it floats without sinking. With the dimes added the effective mass of the box increases by the total mass of the added coins. Calculate the new density for the box (with the dimes inside) and after using Equation 2 (from the theory) to calculate the depth at which it floats, calculate what percent of the block will be underwater with the dimes inside.

3. BILLIARD BALL

The mass of a pool/billiard/snooker ball will be measured in air and when it is submerged in water. From the differences in weight, the volume and density of the ball will be calculated.3.1 MASS IN AIR Use the spring scale to measure the mass of the pool ball in air (ma).

3.2 MASS SUBMERGED

The density of the ball is greater than water so it will sink. With the ball still hanging on the spring scale, submerge it in water and observe that the mass (as shown on the scale) decreases, which is due to the buoyancy force pushing upwards as the ball sinks. Once the ball is fully submerged, record the mass for the submerged ball (mw) from the scale.

3.3 CALCULATING THE VOLUME

The buoyancy force on the ball is the difference between the weights measured in air and water and is also equal to the weight of the water displaced by the submerged ball. Calculate the buoyancy force for the ball, and then use Equation 1 to compute the volume of the ball. 3.4 CALCULATING THE DENSITY

Calculate the density of the ball using the mass (in air) and the volume you just calculated.

The density of phenolic resin is about 1200 kg/m3. The density of celluloid is about 1400 kg/m3. The density of ivory is about 1850 kg/m3. Historically billiard balls have been made from all three materials. Which of the three materials do you believe your ball is made from? (You will explain your decision in your report.)

You use the data and find the answers and using those answer you keep on going and answering.