Welcome to your Density and Pressure(Senior Class Physics Study by Topics) NAME EMAIL PHONE NUMBER 1. A solid weighs 0.040N in air and 0.025N when fully immersed in a liquid of density 800kg/m³. Calculate the volume of the solid 0.000002kg/m³ 0.00002kg/m³ 0.000003kg/m³ 0.0000025kg/m³ 2. Which of the following statements is/are true?I. detergents poured into water increases its surface tension.II. oil poured onto water reduces its surface tension.III. surface tension helps to keep the eggs of water insects aloft. I only I & II only II only III only II & III only 3. A balloon filled with hydrogen rises when released into the air because the upthrust on the balloon is equal to the weight of the balloon the upthrust of the balloon is less than the weight the upthrust on the balloon is greater than the weight of the balloon the pressure below the balloon is greater than that above the balloon the density of the balloon & hydrogen is greater than the density of air 4. A hose of cross- sectional area 0.5m² is used to discharge water from a water tanker at a velocity of 60m/s in 20s into a container. If the container is filled completely, the volume of the container is 6000m³ 2400m³ 240m³ 600m³ 5. Which of the following statements about liquid pressure is NOT correct? The pressure is exerted equally in all directions at any point at any point in a liquid is the same at the same level of a liquid at any point on the wall of its container acts in all directions perpendicular to the wall at a particular depth depends on the shape of the vessel at a point in a liquid is proportional to the depth 6. Which of the following is suitable to use an altimeter? a mercury barometer a mercury manometer an Aneroid barometer a Fortin barometer 7. What is the height of the liquid column in a barometer tube that would support an atmospheric pressure of 102,000N/m² if the density of the liquid is 2,500kg/m³. (g = 10m/s²). 39.23m 3.92m 0.75m 0.76m 8. A piece of wire gauze can be made to lie on water because the water molecules repel the wire gauze upward the wire gauze is less dense than water the water surface has the effect of an elastic thin skin of the cohesive forces between the water and the wire gauze molecules 9. Which of the following is most viscous at room temperature? alcohol water kerosene petrol palm oil 10. What volume of alcohol with a density of 8.4 x 10²kg/m³ would have the same mass as 4.2m³ of petrol whose density is 7.2 x 10²kg/m³? 5.0m³ 5.8m³ 3.6m³ 4.9m³ 1.4m³ 11. A known sprinkler has 20 holes of cross-sectional area 0.02cm² and is connected to a hose pipe of cross-sectional area 0f 2.4cm². If the speed of the water in the hose pipe 1.5cm/s, find the speed of the water as it emerges from the holes. 4m/s 30m/s 1.5m/s 9m/s 12. Which of the following statements is/are correct about the common hydrometer?I. it has a long narrow stemII. the R.D values marked on the stem increases down the stemIII. it has a wide bulbIV. the bulb is loaded to make the hydrometer float vertically I, II & III only II & IV only I, II, III & IV I, III & IV only II only 13. A thin hydrometer floats stationary in water at a temperature of about 20ºc. If the water is gradually cooled to 0ºc, their hydrometer will. oscillate gradually in a vertical plane as long as the cooling continues sink gradually at first and become stationary after some time 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 14. Which of these statements are true of pressure in liquid?I. pressure acts equally in all directionsII. pressure decreases with depthIII. pressure at the same level of a liquid is the sameIV. pressure is dependent on the cross-section area of the barometer tube I, III & IV Only I, II, III & IV I & III Only I, II & III Only 15. Oil from a bottle flows out more easily after it has been warmed because molecules are given potential energy during warming osmotic pressure of the oil is increased cohesion between the oil molecules and those of the bottle is reduced friction between the oil layer is reduced oil molecules force one another out 16. If the relative density of a metal is 19. What will be the mass of 20cm³ of the metal when immersed in water? 400g 180g 360g 380g 39g 17. The density of a solid is defined as the volume per unit mass of the solid mass of the solid compared to the mass of an equal volume of water mass per unit volume of the solid amount of water displaced when a unit mass of solid is immersed in it weight per unit volume of the solid 18. A ship floating in clear water of density 1000kg/m³ moves to sea water of density 1050kg/m³ where it floats again. The upthrust on the ship then? stays constant increases increases by 0.05 times decreases by 0.05 times decreases 19. The mass of a specific gravity bottle is 15.2g when empty. It is 24.8g when filled with petrol and 27.2g when filled with distilled water. Calculate the R.D of petrol. 0.80 1.25 1.10 0.90 20. An object of mass 400g and density 600kg/m³ is suspended with a string so that half of it is immersed in paraffin of density 900kg/m³. The tension in the string is 5N 4N 1N 3N 21. A cube of sides 0.1m hangs freely from a string. What is the upthrust on the cube when totally immersed in water? 700N 10N 110N 1000N 22. A piece of cork floats in a liquid. What fraction of its volume would be immersed in the liquid? (density of the cork = 0.25 x 10³kg/m³, density of the liquid = 1.25 x 10³kg/m³). 0.2 0.5 0.8 0.1 23. 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. 0.2N/m² 200N/m² 20N/m² 2N/m² 24. A steady flow of water passes along a horizontal tube from a wide section X to the narrower section Y. Manometers are placed at P & Q as shown below. Which of the statements is correct? the manometer at P shows greater pressure than at Y the manometer at P shows lower pressure that an Q water velocity at X is greater than at Y kinetic energy of water at X = kinetic energy at Y pressure at X is less than at Y 25. 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) 3.7 10.5 3.84 17.3 1 out of 25 Time is Up! Time's up
