Welcome to your Density and Pressure(Senior Class Physics Study by Topics) NAME EMAIL PHONE NUMBER 1. An object of mass 'm', volume 'v' is totally immersed in a liquid of density 'ρ'. The tension of a string holding it is (m - ρV)g (m + ρV)g mg ρVg (mg)/(m - ρV) None 2. If a plastic sphere floats in liquid (density = 1000kg/m³) with 0.5 of its volume submerged and floats in oil with 0.4 of its volume submerged, the density of the oil is 2000kg/m³ 800kg/m³ 1200kg/m³ 1250kg/m³ None 3. Oil from a bottle flows out more easily after it has been warmed because osmotic pressure of the oil is increased friction between the oil layer is reduced oil molecules force one another out molecules are given potential energy during warming cohesion between the oil molecules and those of the bottle is reduced None 4. A thin hydrometer floats stationary in water at a temperature of about 20ºc. If the water is gradually cooled to 0ºc, their hydrometer will. rise gradually at first and becomes stationary after some time neither rise nor fall but remains at a constant level rise gradually at first then begins to sink slowly sink gradually at first and become stationary after some time oscillate gradually in a vertical plane as long as the cooling continues None 5. Calculate the pressure on Radeyah's thumb when she exerts a force of 20N and the top of the pin is square, the length of each side being 10mm0.2N/mm² 12N/mm² 2N/mm² 20N/mm² 0.2N/mm² None 6. When a paint brush is removed from clean water, the bristles of the brush are pulled together because of the viscousity of the surrounding the weight of the brush bristles the mass of the brush bristles surface tension low density of water None 7. At what depth below the sea-level would one experience a change of pressure equal to one atmosphere? (density of sea water = 1013kg/m³; one atm = 101,000N/m²; g = 10m/s²) 0.1m 1m 100m 10m None 8. A balloon filled with hydrogen rises when released into the air because the density of the balloon & hydrogen is greater than the density of air the upthrust on the balloon is equal to the weight of the balloon the upthrust of the balloon is less than the weight the pressure below the balloon is greater than that above the balloon the upthrust on the balloon is greater than the weight of the balloon None 9. A liquid of mass 1000kg fills a rectangular tank of length 2m. If the tank is 4m high, what is the pressure at the middle of the tank? 2,000N/m² 10,000N/m² 1,000N/m² 1,500N/m² None 10. Two capillary tubes of the same bore are dipped into water and mercury respectively. The water level rises in one tube while the mercury level falls in the other. This is because the adhesive force between mercury and glass is greater than the cohesive force of mercury mercury is denser than water the adhesive force between water and glass is greater than the cohesive force of water the cohesive force of water is equal to the adhesive force between water and glass the molecules of mercury have stronger bonding than those of water None 11. In an experiment using the relative density bottle, the following results were recorded.Mass of an empty bottle + stopper = 50gMass of a bottle full of water + stopper = 80gMass of bottle full of liquid Q + stopper = 74gUse these results to calculate the relative density of liquid Q 0.93 0.80 1.60 0.60 1.25 None 12. A rectangular solid block has length 10cm, breadth 5cm and height 2cm. If its lies on a horizontal surface and has density 100kg/m³, calculate the pressure it exerts on the surface. 20N/m² 200N/m² 2N/m² 0.2N/m² None 13. A spherical metal ball falling through a viscous liquid is acted upon by the I. weight of the ballII. viscous force of the liquid on the ballIII. upthrust of the liquid on the ball I, II & III I & II only I & III only II & III only None 14. I. massII. densityIII. temperatureIV. nature of substanceWhich of the above affects diffusion? II, III & IV only all of the above none of the above I, II & IV only I & II only None 15. A spiral spring, loaded with a piece of metal, extends by 10.5cm in air. When the metal is fully submerged in water, the spring extends by 6.8cm. Calculate the relative density of the metal. (Assume Hooke's law is obeyed) 10.5 3.7 17.3 3.84 None 16. A man on a bench will exert the greatest pressure on the bench when he Stands on one foot only Stands on the toes of one foot stands on both feet lies flat on his belly lies flat on his back None 17. If the relative density of a metal is 19. What will be the mass of 20cm³ of the metal when immersed in water? 400g 39g 380g 360g 180g None 18. As a result of air at the top of a barometer, the height of the mercury column is 73.5cm when it should be 75cm, the volume of the space above the mercury is 8cm³. Calculate the correct barometric height when the barometer reads 74cm and the volume of the space above the mercury is 6cm. 72cm 76cm 75.1cm 74.5cm None 19. A parachute attains a terminal velocity when the viscous force of the air is equal to the sum of the weight and upthrust it expands as a result of reduced external pressure the viscous force of the air and the upthrust completely counteract its weight its density is equal to the density of air None 20. The diagram below shows 3 identical blocks of wood floating in liquids P, Q & R. Which of the following statements is correct? the volumes of the blocks below the liquid surface are the same the upthrust on each block is the same the upthrust decreases as the temperatures of the liquids fall the blocks will sink more as the temperatures of the liquids fall the upthrust increases as the temperatures of the liquids fall None 21. Which of the following is obeyed if a force on a sphere moving through a viscous fluid is proportional to its speed, radius and viscosity? Bernoulli's law Pascal's principle Archimedes' principle Stoke's law None 22. A solid of weight 0.6N is totally submerged in oil and water respectively. If the upthrust in oil is 0.21N and the R.D of oil is 0.875, find the upthrust in water. 0.360N O.18N 0.24N 0.6N None 23. A steel needle floating on the surface of water sinks when kerosene is added to the water because kerosene causes an increase in the density of water kerosene causes an increase in the surface tension of water kerosene causes a decrease in the density of water a steel needle is denser than kerosene kerosene causes a decrease in the surface tension of water None 24. A balloon of volume 100m³ and mass 2kg is filled with helium of density 0.18kg/m³ at ground level. The surrounding air has a density of 1.28kg/m³. Calculate the maximum mass which the balloon can lift off the ground. 128kg 108kg 120kg 85kg None 25. It is observed that water will wet a clean glass because the adhesion of water molecules is weaker than the cohesion of water to glass cohesion of water to glass is stronger than the cohesion of water molecules cohesion of water to glass is weaker than the cohesion of water molecules adhesion of water molecules is stronger than the cohesion of water molecules None 1 out of 25 Time's upTime is Up!
