ull,{"backHref":"/gcse/physics/edexcel/questions","basePath":"/gcse/physics/edexcel/pressure-in-fluids-and-upthrust/questions","formulaUrl":null,"initialIndex":96,"initialQuestionWindow":[{"id":"97822df4-0c84-43a5-a8a6-1e81e8beaa7b","revisionId":"459bbe8e-1b2c-437e-991a-c46f36fade47","questionNumber":null,"questionType":"LA","specification":"Figure 1 shows a cross-section of a rectangular cargo barge floating on a calm river, first when empty, and second when loaded with heavy shipping containers.\n\n![A diagram showing two cross-sectional views of a rectangular cargo barge floating in a river. The left view shows the empty barge floating at a shallow depth with the water line near its bottom. The right view shows the same barge loaded with three heavy rectangular shipping containers, with the barge submerged much deeper in the water so the water line is near its deck. Labels show: 'Water level', 'Empty barge', and 'Loaded barge'.](https://assets.mathsgenie.co.uk/aqa-qb/add81581-4360-4788-bf9b-ffad2e35fce5.png)\n\nThe barge floats lower in the water when carrying the cargo containers than when it is empty.","difficulty":7,"difficultyBand":"medium","totalMarks":6,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"ad92b411-e7ff-42db-8224-f1ba5c9a0b59","label":null,"content":"Explain why the barge floats when empty, and why it floats lower in the water when it is carrying the heavy cargo.","markscheme":"- Identifies that for an object to float, the downward force of its weight must be balanced by an upward upthrust force (equilibrium of forces) B1\n- States that upthrust is equal to the weight of the water displaced by the submerged volume of the barge (Archimedes' principle) B1\n- Explains that the empty barge has a relatively small weight, which is balanced by the upthrust from a small volume of displaced water B1\n- Explains that adding shipping containers increases the overall weight of the barge system B1\n- Explains that to remain floating, the upward upthrust must increase to balance this new, larger total weight M1\n- Connects this directly to sitting lower: the barge must submerge further to displace a larger volume of water to generate the required larger upthrust A1","marks":6,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"forces_and_displacement","label":"Balance forces and displacement","steps":[{"type":"text","order":0,"title":"Balance the empty barge","content":"For the empty barge to float without moving up or down, the forces must be in **equilibrium** (balanced): its downward weight equals the upward **upthrust** from the water. This earns **B1**.","highlights":[{"text":"The barge floats lower in the water when carrying the cargo containers than when it is empty.","location":"specification"}]},{"type":"text","order":1,"title":"Link upthrust to water","content":"Upthrust is equal to the **weight of the water displaced** by the submerged volume of the barge. *Displaced water* is the water that the submerged part of the barge takes the place of. This earns a further **B1**.","highlights":[{"text":"The barge floats lower in the water when carrying the cargo containers than when it is empty.","location":"specification"}]},{"type":"text","order":2,"title":"Explain the empty barge","content":"When empty, the barge has a relatively small weight. A small volume of submerged barge displaces a small weight of water, producing enough upthrust to balance that small weight. This earns the third **B1**.","highlights":[{"text":"first when empty","location":"specification"}]},{"type":"text","order":3,"title":"Add the cargo weight","content":"Putting heavy shipping containers on the barge increases the overall weight of the barge-and-cargo system. This earns **B1**.","highlights":[{"text":"loaded with heavy shipping containers","location":"specification"}]},{"type":"text","order":4,"title":"Increase the upthrust","content":"The loaded barge still floats, so its forces must again be balanced. Its larger downward we

Pressure in fluids and upthrust

Question 17

Pressure in fluids and upthrust Questions

Pressure in fluids and upthrust

Question 17

Pressure in fluids and upthrust Questions