Archimedes Principle An object, part aluminum, part wood, floats in water.

Two blocks are cemented together top to bottom and the whole object is placed in water. Known values are the density of the wood Dw= .650 kg/m^3, of aluminum Da = 2700 kg/m^3, and of water Dliq= 1000 kg/m^3. See attachment #1 for diagram, (not to scale). PART a. If the object barely floats, with the top surface ot the wood level with the surface of the water, find the ratio of the volumes, Vw/Va. PART b. With the object barely floating, if the mass of the aluminum part is Ma= 8 kg, find the mass of the wood part. PART c. If the object floats with the wood only 75 percent submerged, find the ratio of the volumes, Vw/Va.

Pressure vs depth in liquid and total force on submerged rectangular and triangular surfaces.

A solid prism has a vertical rectangular face of height H= .90 m by width W=.5 m and a horizontal rectangular face of length L= 1.2 m, with W=.5 m also. The prism is submerged in liquid whose density is D= 1600 kg/m^3 with the horizontal face at depth B= .35 m. See attachment #1 for a diagram showing parameters. PART a. Find the total force exerted by the liquid on the horizontal rectangular surface of length L by width W at depth B. PART b. Find the total force exerted by the liquid on the vertical rectangular surface, height H, width W, top edge at depth B. PART c. Find the total force exerted by the liquid on the vertical triangular face with edge H vertical and edge L horizon... click for more

Working with power, force and efficiency in a speed problem.

A 7.5 x 10^4 W motor that is 75% efficient exerts an average force of 3.5 x 10^3 N to move a boat at a constant speed. How fast is the boat moving? NOTE: efficiency = output/input. Motors are rated as to their input. 7.5 x 10^4 is the power input.

Calculation of angle of tilt and tension in a string.

A body of mass 10 kg is suspended by a light inextensible string from the roof of a train. Calculate the tension in the string and its inclination to the vertical when the train A. moves with a fixed velocity of 36 km/h. B. accelerates at 2 ms-2, C. decelerates at 6 ms-2

straight forward short calculation

A 12 pound force can lift a 150 pound force on a hydraulic lift. The smaller of the two cylinders has a cross-sectional area of 20cm^2. Calculate the cross-sectional area of the larger cylinder.