3.0 Buoyancy | HGE | CE Board Exam Review

#HGE #Hydraulics&GeotechnicalEngineering What's up mga bees! For this video we will be talking about Buoyancy; Archimedes Principle. Timestamps: 00:00 Lecture 07:24 Past Board Exam Problems 1. A barge weighing 350kN when empty is 6m wide, 15m long and 3m high. Floating upright, evaluate the draft of the barge in meters when transporting 5000bags of cement along a river, each bag having a mass of 40kg. Assume the specific gravity of the river to be 1.02. (2.57m) 2. A piece of rock weighs 360N in air and when submerged in water it weighs 250N. • Evaluate the volume of the rock in m3. (0.0112m3) • Evaluate the unit weight of the rock in kN/m3 (31.25kN/m3) • Evaluate the specific gravity of the rock. (3.19) 3. A solid block having SG=3.5 placed in a container containing liquid having a specific gravity if 13.6. • If the volume of the block is 0.02 cu.m. obtain the weight of the block in Kn. (0.687kN) • Evaluate the percentage volume of the block that floats above the liquid surface. (74.3%) • Obtain the downward force in kN required to make the it completely submerged in the liquid. (1.98kN) 4. A ship having a displacement of 24000 tons and a draft of 10.5m in the ocean enters a harbor of fresh water. If horizontal cross section of the ship at the water line is 3000 sq.m., what depth of fresh water is required to float the ship? Assume a marine tone is 1000 kg and that seawater and fresh water weighs 10.1kN/m3 and 9.81kN/m3 respectively. (10.73m) 5. A ship with vertical sides near waterline weighs 40MN including its cargo and has a draft of 6.7m in seawater (SG=1.026). Unloading 2MN of its cargo, the draft decreases to 6.4m. With its cargo reduced, the ship enters a harbor of fresh water. Evaluate the draft of the ship in fresh water, in meters (6.56m). 6. A concrete cube 0.60m on an edge weighing 23.5kN/m3 is placed at the bottom of the tank in which seawater (SG=1.03) stands 5m deep. The bottom edges are sealed off so that no water is admitted under the block. Evaluate the vertical pull required to lift the block in kN. (21.08kN) A block of wood having a length “h” and a constant cross section A floats vertically in water with 50mm above the water surface. When placed in another liquid with specific gravity of 1.35, the block projects 75mm projecting above the liquid surface. Evaluate the following: • Obtain the “h” in mm. (146mm) • Specific gravity of wood. (0.658) • If the wood is vertically submerged in seawater (SG=1.03), by how many mm would project out if the water surface? (52.73mm) 7. A spherical ballon 6m in diameter is filled with gas weighing 5kN/m3 in standard air weighing 12kN/m3, what is the maximum load in kN excluding its own weight, that the balloon can lift? (792kN) A container has two layers of different liquids, one having a SG=1.2 and the other having a SG=1.5. A solid spherical metal having a diameter of 200mm and specific gravity of 7.4 is submerged in such a manner that half of the sphere is on the top layer and the other half in the bottom layer of liquid. • Evaluate the buoyant force acting on the sphere, in Kn. (0.055kN) • Determine the tension in the cable attached to the sphere to normal position in kN. (0.249Kn) • If both liquids are water, evaluate the buoyant force acting on the sphere. (0.0411kN) SUBSCRIBE TO JABEE TV | http://www.youtube.com/c/JABEETV?sub_... OUTRO MUSIC CREDITS: __________________________________________________________________ Song: Sineskwela-Mathtinik Violin Lead Instrumental Medley Instrumental by: Chords (YT Channel) Link:    • Sineskwela-Mathtinik Violin Lead Instrumen...   __________________________________________________________________ Song: Math Tinik Opening Song - mof!us (Remix) Remix By: mof!us (YT Channel) Link:    • Math Tinik Opening Song - mof!us (Remix)   __________________________________________________________________ The outro music was an original work of Ting-ting Calzo-Fournier and Jungee Marcelo which was used as a theme song of the 90's kids program of ABS-CBNS "Mathtinik". The outro line was also adapted from the lyrics of the song "maglakbay, mag-enjoy, maglaro, manaliksik, maging Mathinik". The outro music is not ours but belongs to their respective owners. Book References: -"Licensure Exams for Civil Engineering" by BESAVILLA Kung sakali may mali po or mga katnanungan kayo, kindly comment down below at sasagutin po natin yan :)