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Solve Exercise C1 page 25 Physics 8 Textbook
Exercise:
Among the forces listed below figure 7.3a and b, which force is pressure?
Solution:
a) The force of the tractor acting on the road surface.
b) Both forces.
Solve Exercise C2 page 26 Physics 8 Textbook
Exercise:
Based on the experiment in figure 7.4, determine the factors on which the effect of pressure depends by comparing pressures, pressed areas, and depression of the metal block into powder or fine sand in case (1) with case (2), of case (1) with case (3).
Find the appropriate '=', '>', '<' signs for the blank cells of the table.
Solution:
Table 7.1: Comparison Table
Solve Exercise C3 page 26 Physics 8 Textbook
Exercise:
Choose appropriate words for the blanks in the conclusion below:
The effect of pressure is greater when pressure is ...(1)... and the pressed area is ...(2)...
Solution:
(1) stronger.
(2) smaller.
Solve Exercise C4 page 27 Physics 8 Textbook
Exercise:
Based on which principle do we increase or decrease pressure? Provide examples of increasing and decreasing pressure in real life.
Solution:
- Pressure is calculated by the magnitude of the force on a unit area being pressed:
where: p is pressure, F is the force acting on the pressed surface with area S.
- Example: The thinner the blade, the sharper the knife, because under the same pressure, if the pressed area is smaller (thin blade), the effect of the pressure is greater (knife is easier to cut objects).
Solve Exercise C5 page 27 Physics 8 Textbook
Exercise:
A tank weighs 340,000N. Calculate the pressure exerted by the tank on the horizontal road surface, knowing that the contact area of the tracks with the ground is 1.5m2. Compare this pressure with the pressure of a car weighing 20,000N with the contact area of the wheels with the ground being 250cm2. Based on the calculated results above, answer the question posed in the opening part.
Solution:
Comparison:
Thus, the pressure exerted by the tank on the horizontal road surface is lower than the pressure exerted by the car. Therefore, the tank can run on soft ground.
- The heavier tractor can run on soft ground because it uses wide tracks, resulting in lower pressure caused by the weight of the tractor. Whereas the car uses wheels (small pressed area), resulting in higher pressure caused by the weight of the car.
In the 8th-grade Physics Chapter I Mechanics program, students will learn about Atmospheric Pressure. Let's solve exercises on pages 32, 33, 34 Physics 8 to master this lesson.
In Chapter I Mechanics of Physics 8, students will learn about Liquid Pressure - Communicating Vessels along with Solving exercises on pages 28, 29, 30, 31 Physics 8.
