Question 1
Figure 1 shows a micrometer with a negative error of 0.02 mm, used to measure the diameter of a ball bearing.
Record the diameter of the ball
Answer
equivalent to
5.5 + 42⁄100
5.92 + 0.02 = 5.94mm
5.5 + 42⁄100
5.92 + 0.02 = 5.94mm
Question 2
The figure 2 below shows the behaviour of mercury in a capillary tube.
Explain the behaviour.
Answer
- Cohesion between mercury molecules is greater than adhesion between mercury and glass.
- The mercury sinks down the tube to enable molecules to keep together.
- The mercury sinks down the tube to enable molecules to keep together.
Question 3
Figure 3 shows apparatus used to observe the behaviour of smoke particles in a smoke cell.
a) Explain what was observed
b) Explain what would happen if the temperature was raised.
Answer
a) Bright specs are seen moving in a continuous random motion.
They are moving in a continuous random motion due to the uneven bombardment by air molecules showing that air is made up of particles which are in a constant motion.
b) Rate of collision increases due to increase in overall kinetic energies of air molecules
b) Rate of collision increases due to increase in overall kinetic energies of air molecules
Question 4
The figure 4 below shows two horizontal pipes A and B connected to two identical vertical tubes. Water flows in pipe A at a velocity V1 and in pipe B at a velocity V2. Explain why the level of water in tube T in B is lower than that of tube T in A
Answer
By equation of continuity V2 is greater than V1 ; ( Since A1} A2) and by Bernoulli's principle P2 is less
than P1 hence level in B is lower than level in A
Question 5
Two 10g masses are fixed onto two similar aluminum plates, one polished and the other painted black, using wax as shown in the figure below. A Bunsen flame is placed mid way between the plates
Give and explain the observation made
Answer
Observation : Mass on the dull plate falls off before, that on shiny / polished plate
Explanation : dull surfaces are better absorbers of heat or shiny surfaces are poor absorbers of heat
Explanation : dull surfaces are better absorbers of heat or shiny surfaces are poor absorbers of heat