PART ONE: in Water

PHYSICS WORKSHEET A BUOYANCY NAME: ______DATE: _____

PART ONE: In water 1. A cube measures 10 cm on each side. This box has a mass of 100 grams. It floats when it is placed in water.

A. What is the mass of the water that is displaced? ______

B. What is the volume of the water that is displaced? ______

C. What is the volume of the box that is submerged? ______

D. To what depth will the box sink? Data Equations Math Answer

E. If 20 pennies (3.0 grams each) are placed in the box, what will be its new depth? Data Equations Math Answer

2. A cube of wood is 12.3 cm on each side and has a mass of 850 grams. To what depth will it sink in water? Data Equations Math Answer

3. A block of metal has a mass of 150 grams. When it is submerged in water its weight drops to 0.926 N. A. What is the weight of the block? Data Equations Math Answer

B. What is the apparent loss of weight when it is submerged? Data Equations Math Answer

C. What is the buoyant force on the block? ______

D. What is the mass of the water that is displaced by the block? Data Equations Math Answer

E. What is the volume of the water that is displaced by the block? ______

F. What is the volume of the block? ______

G. What is the density of the block? Data Equations Math Answer H. What metal is the block made of? ______

4. A 65.4 cm tall solid aluminum cylinder with a diameter of 22.8 cm is dropped off a boat and sinks. What will be its apparent weight under the water? Data Equations Math Answer

PART TWO: In air

Some basic information

Densities of various gasses at different temperatures in kg/m3

Dry Air @ 0°C = 1.29 Dry Air @ 20°C = 1.21 Dry Air @ 30°C = 1.16 Hydrogen @ 0°C = 0.090 Oxygen @ 0°C = 1.43 Helium @ 0°C = 0.178

We always go ballooning on VERY cold days when the ambient air temperature is 0°C

Our balloons are all perfect spheres unless it says otherwise.

1. Our mythical massless balloon is a sphere with a radius of 10 meters.

A. What is the volume of the balloon? Data Equations Math Answer

B. How many kilograms of air can it hold at 0°C? Data Equations Math Answer

C. If this air is heated to 30°C and the volume remained constant, what would its mass be? Data Equations Math Answer

D. How many kilograms could our hot air balloon lift on this cold day? Data Equations Math Answer

E. If we filled our balloon with Hydrogen as opposed to 30°C air, how many kilograms would we use? Data Equations Math Answer F. How many kilograms could our Hydrogen balloon lift on this very cold day? Data Equations Math Answer

2. What is the lift of a spherical balloon with a 12.3 m radius on a VERY cold day if it is filled with Helium? Data Equations Math Answer

3. We have purchased a gigantic can-shaped hot-air balloon with our favorite beverage company’s logo printed on the side. Our pride and joy is 22.6 m tall and 15.8 m across and has a mass of 200 kg when it in deflated. How many kilograms can we lift with our balloon on a very cold day if the heater will only get the air inside the balloon to 20°C? Data Equations Math Answer

4. Crazy Timmy wants to fly across the park by holding onto some spherical helium balloons that are each 50 cm across. A. How many kg of helium are in each balloon? Data Equations Math Answer

B. How many kilograms could each helium balloon lift on a 20°C day? Data Equations Math Answer

C. If Timmy has a mass of 45.6 kg, how many balloons does he need to buy? Data Equations Math Answer

5. What is the lifting power of a spherical hydrogen balloon with a radius of 23.4 m and a mass of 1200 kg when it is deflated if it is used on a very cold day? Data Equations Math Answer