Question 17N.3.HL.TZ0.11a.i
| Date | November 2017 | Marks available | [Maximum mark: 2] | Reference code | 17N.3.HL.TZ0.11a.i |
| Level | HL | Paper | 3 | Time zone | TZ0 |
| Command term | Determine | Question number | a.i | Adapted from | N/A |
The diagram shows a simplified model of a Galilean thermometer. The thermometer consists of a sealed glass cylinder that contains ethanol, together with glass spheres. The spheres are filled with different volumes of coloured water. The mass of the glass can be neglected as well as any expansion of the glass through the temperature range experienced. Spheres have tags to identify the temperature. The mass of the tags can be neglected in all calculations.
Each sphere has a radius of 3.0 cm and the spheres, due to the different volumes of water in them, are of varying densities. As the temperature of the ethanol changes the individual spheres rise or fall, depending on their densities, compared with that of the ethanol.
The graph shows the variation with temperature of the density of ethanol.
Using the graph, determine the buoyancy force acting on a sphere when the ethanol is at a temperature of 25 °C.
[2]
density = 785 «kgm−3»
« =» 0.87 «N»
Accept answer in the range 784 to 786
