#### What makes a ship float?

How is it that ships made largely of steel can float when the density of steel is much higher than the density of water? Why is it possible to make oil tankers much larger than other ships (and what happens when an oil tanker is unloaded?)

#### Center of Mass....

Two astronauts, with masses of 60 kg and 80 kg, are initially at rest in outer space. They push each other apart. What is their separation after the lighter astronaut has moved 12 m? Please provide detailed explanation

#### Comparing Densities

A 40lb container of peat moss measures 14x 20x 30 in. A 40lb container of topsoil has a volume of 1.9 gal. Calculate the average densities of peat moss and topsoil in units of g/cm3. Would it be correct to say that peat moss is "lighter" than topsoil? Explain.

#### Physics - Mechanics - Moments

A very light rod connects two masses, m1and m2. The rod is to be suspended by a string so that it hangs horizontally. Given that the length of the rod is D = 63.0 cm, find the appropriate position of the string (the distance x, as shown in the figure) for each of the following cases. (a) m1 = 0.81 ...

#### Various Unit Conversions

Convert to the unit of measure indicated. Take values out to 3 decimal places when appropriate. 4 pounds =______kilograms 25 miles =_______kilometers 1 meter =________millimeters 10 liters =_______quarts 85 kilometers =________centimeters 10 meters =________yards 87 liter =__________millili...

#### Magnitude and Acceleration and Tension

Two blocks, of weights 3.6 N and 7.2 N, are connected by a mass-less string and slide down a 30 degree inclined plane. The coefficient of kinetic friction between the lighter block and the plane is 0.10; that between the heavier block and the plane is 0.20. Assuming that the lighter block leads, fin...

#### Questions on basic mechanics

1) Two spherical bodies have masses of 60 and 80 kg, respectively. Determine the force of gravity acting between them if the distance from center to center of the bodies is 500 mm. A) 5.34(10**-7) N B) 0.890(10**-6) N C) 0.890(10**-6) kN D) 1.123(10**6) N 2) How many barrels of oil are contai...

#### Tension and Moments

A 20.0 kg floodlight in a park is supported at the end of a horizontal beam of mass 20.0 kg and length L that is hinged to a pole (beam and pole are perpendicular). A cable at an angle of 30.0 degrees with the beam helps to support the light. a) Find the tension in the cable. b) Find the horizo...

#### Human visual resolution

The human visual resolution is 1 minute of arc. Assuming that you are looking down an isolated road at night. a. at what distance can you distinguish the two headlights of an approaching car? A one-inch telescope can resolve two points of light 4.5 arc seconds apart. b. At what dist...

#### Coherent Light Beams

If two light beams are coherent, which of the following is NOT necessary? a. they must have the same velocity b. they must have a constant phase differnce at every point in space c. they must have the same frequency d. they must have the same wavelength e. they must have the same amplitude

#### Determining light beams and displacement

A light beam composed of red and blue light is incident upon a rectangular glass plate. The light emerges into the air from point P as two separate beams a. that are parallel, with the red beam displaced below the blue beam. b. that are not parallel, with the blue beam displaced below the red b...

#### Angular Resolution of a Wavelength

The angular resolution of a 30 meter diameter radio telescope observing a radio signal of 21 centimeters would be X arcseconds,while the angular resolution of the fully dilated human eye,with diameter of about 5 mm, gathering light at an average of 6x10^(-7) meters in wavelength would be Y?

#### Gauge pressure, membrane in closed container

Two parts of a closed container are separated by a membrane which only allows the passage of water. Initially each container holds 5 liters of deionized water. To one side is added 22 grams of chlorine and to the other side is added 15 grams of potassium. Each side has a pressure gauge. Which side w...

#### High Rise Apartment Block and Water Flowing

You live in the ground floor of a high rise apartment block. The over head water tanks which supply water to all the apartments are situated on the rooftop. When water flow through the taps in your apartment is low, you go to inspect the water level in the tank on the rooftop. You check the water ...