E. Short-answer questions
1. Suggest a method to determine the area of
determine the
an irregular-shaped object.
2. Name the method used to
volume of an irregular object.
3. Name the devices used to measure the
volumes of liquids in the laboratory
4. What is the correct way of taking the
reading of the liquid level in a measuring
cylinder?
5. Why do different substances of the same
volume have different masses?
6. It is more convenient to store 100 kg of
steel than 100 kg of cotton. Explain why.
7. What are the SI and common units of
density? Write the relation between them.
8. What do you understand when we say that
the density of copper is 8.9 g/cm?
9. Define speed. Write its SI unit.
Answers
Answer:
1. One method for finding the area of an irregular shape is to divide the shape into smaller shapes which you do have the formula for. Then you find the area of all of the smaller shapes and add all of your areas together.
2. Displacement is usually the method that is used to measure the volume of an irregularly shaped object. The object is simply submerged in a liquid and the volume of liquid that is displaced is measured.
3. A graduated cylinder, also known as measuring cylinder or mixing cylinder is a common piece of laboratory equipment used to measure the volume of a liquid.
4. Place the graduated cylinder on a flat surface and view the height of the liquid in the cylinder with your eyes directly level with the liquid. The liquid will tend to curve downward. This curve is called the meniscus. Always read the measurement at the bottom of the meniscus.
5. Equal masses of different substances have different volumes. For example, the volume of cotton is much larger than the volume of an equal mass of lead. This is because the particles of lead are closely packed while those of the cotton are very loosely packed. ... Equal volumes of different substances have different masses.
6. Density of steel is 8 g/cm³ while that of cotton is 1.5 g/cm³. Since we know that density is inversely proportional to volume, and hence, item with low density would require more volume, and therefore space. So, as more space is required to store cotton, it is less convenient than storage of steel.
7. The SI unit of kilogram per cubic metre (kg/m3) and the cgs unit of gram per cubic centimetre (g/cm3) are probably the most commonly used units for density. One g/cm3 is equal to 1000 kg/m3. One cubic centimetre (abbreviation cc) is equal to one millilitre.
8. The density of copper is 8.9g cm-3. What is the meaning of this statement ? It determines the compactness of the body. So, The density of copper is 8.9g cm-3 means in every cm3 volume of Cu 8.9 g mass is contained
9. Speed is defined as the distance traveled by a body per unit time. its unit in SI is m/s.
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