When the gas tap is opened, gas flows at high speed creating a low pressure region above the nozzle. The higher atmospheric pressure on the outside pushes air in and the gas burns.
johnmulu answered the question on May 15, 2017 at 10:22
- Figure 5 shows parts A, B and C of a glass tube. (Solved)
Figure 5 shows parts A, B and C of a glass tube.
State with a reason the part of the tube in which the pressure will be lowest when air is blown through the tube from A towards C.
Date posted: May 15, 2017. Answers (1)
- Figure 7 shows part of a petrol engine, in which air flowing under atmospheric pressure passes into a constriction, where it mixes with petrol. The mixture then flows into a combustion cylinder. (Solved)
Figure 7 shows part of a petrol engine, in which air flowing under atmospheric pressure passes into a constriction, where it mixes with petrol. The mixture then flows into a combustion cylinder.
Explain what causes the petrol to move from the petrol chamber to the air steam in the constriction when the piston is moved downwards.
Date posted: May 15, 2017. Answers (1)
- Figure 4 shows a horizontal tube with two vertical tubes x and y. Water flows through the horizontal tube from right to left. The water level in the tube x is higher than water level in tube y(Solved)
Figure 4 shows a horizontal tube with two vertical tubes x and y. Water flows through the horizontal tube from right to left. The water level in the tube x is higher than water level in tube y
Explain this observation.
Date posted: May 15, 2017. Answers (1)
- Figure 6 shows two inflated balloons hanging vertically on light threads. (Solved)
Figure 6 shows two inflated balloons hanging vertically on light threads.
When a stream of air is blown in the space between the balloons, they are observed to move towards each other. Explain this observation
Date posted: May 15, 2017. Answers (1)
- Figure 6 shows a sheet of paper rolled into a tube(Solved)
Figure 6 shows a sheet of paper rolled into a tube
When a fast stream of air is blown into the tube as shown in the diagram the paper tube collapses. Explain the observation.
Date posted: May 15, 2017. Answers (1)
- Figure 2 shows a tube of varying cross sectional area. V1, V2, V3 and V4 represent the speed of water as it flows steadily through the sections of the tube(Solved)
Figure 2 shows a tube of varying cross sectional area. V1, V2, V3 and V4 represent the speed of water as it flows steadily through the sections of the tube
Arrange the speed V1, V2, V3 and V4 in decreasing order starting with the highest
Date posted: April 19, 2017. Answers (1)
- Figure 19 shows a pith ball placed in a flask. When a jet of air is blown over the mouth of the flask as shown, the pith ball is observed to rise from bottom.(Solved)
Figure 19 shows a pith ball placed in a flask. When a jet of air is blown over the mouth of the flask as shown, the pith ball is observed to rise from bottom.
Explain this observation
Date posted: April 19, 2017. Answers (1)
- A student holds a sheet of paper at one end so that it hangs in the position A as shown in Figure 14(Solved)
A student holds a sheet of paper at one end so that it hangs in the position A as shown in Figure 14
If the cross-sectional area A1 at P is less than A2 at Q, state how the liquid velocity V2 at Q compares with velocity V1 at P.
Date posted: April 19, 2017. Answers (1)
- Figure 1 shows a section of a pipe PQ. A constant pressure difference maintains a streamline flow of a liquid in the pipe.(Solved)
Figure 1 shows a section of a pipe PQ. A constant pressure difference maintains a streamline flow of a liquid in the pipe.
If the cross-section area A1 at P is less than A2 at Q, state how the liquid velocity V2 at Q compares with velocity V1 at P.
Date posted: April 19, 2017. Answers (1)
- Fig. 9 shows a Bunsen burner.(Solved)
Fig. 9 shows a Bunsen burner.
Use Bernoulli's principle to explain how air is drawn into the burner, when, the gas tap is opened.
Date posted: April 19, 2017. Answers (1)
- Figure 12 shows a displacement - time graph for a progressive wave(Solved)
Figure 12 shows a displacement - time graph for a progressive wave
i) State the amplitude of the wave
ii) Determine the frequency of the wave.
Date posted: April 19, 2017. Answers (1)
- Figure 2 shows how the displacement varies with time for a certain wave(Solved)
Figure 2 shows how the displacement varies with time for a certain wave
Determine the frequency of the wave.
Date posted: April 19, 2017. Answers (1)
- Figure 4 shows the displacement - time graph for a certain wave(Solved)
Figure 4 shows the displacement - time graph for a certain wave
Determine the frequency of the wave
Date posted: April 19, 2017. Answers (1)
- A long coil is attached to a vibrating blade as shown in Figure(Solved)
A long coil is attached to a vibrating blade as shown in Figure
State the type of mechanical wave generated by the set-up and mark alongside the coil, the length corresponding to the wavelength, wavelength of the wave.
Date posted: April 19, 2017. Answers (1)
- Figure 10 represents a transverse wave of frequency 5 Hz traveling in the X direction. Determine the speed of the wave.(Solved)
Figure 10 represents a transverse wave of frequency 5 Hz traveling in the X direction. Determine the speed of the wave.
Date posted: April 19, 2017. Answers (1)
- Figure 5 shows the displacement time graph of a wave travelling at 200 cm/s.(Solved)
Figure 5 shows the displacement time graph of a wave travelling at 200 cm/s.
Determine for the wave, the
i) Amplitude
ii) Period
iii) frequency
iv) Wavelength
Date posted: April 19, 2017. Answers (1)
- Figure 3 shows a transverse wave traveling along x-axis(Solved)
Figure 3 shows a transverse wave traveling along x-axis
i) Determine the:
I. Wavelength of the wave
II. Amplitude of the wave
ii) If the time taken by the wave to move from O to A is 0.90 seconds, determine the:
I. frequency of the wave
II. Speed of the wave
Date posted: April 19, 2017. Answers (1)
- The three springs shown in figure 7 are identical and have negligible weight. The extension produced on the system of springs is 20 cm.(Solved)
The three springs shown in figure 7 are identical and have negligible weight. The extension produced on the system of springs is 20 cm.
Determine the constant of each spring.
Date posted: April 19, 2017. Answers (1)
- Table 1 shows the results of an experiment carried out to study the properties of a spring
(Solved)
Table 1 shows the results of an experiment carried out to study the properties of a spring
State with a reason whether the experiment was done within the elastic limit of the spring.
Date posted: April 19, 2017. Answers (1)
- Figure 2 shows a spring balance. Its spring constant is 125Nm-1. The scale spreads over a distance of 20 cm.
(Solved)
Figure 2 shows a spring balance. Its spring constant is 125Nm-1. The scale spreads over a distance of 20 cm.
Determine the maximum weight that can be measured using the spring.
Date posted: April 19, 2017. Answers (1)