Answer the following questions.
(a) Define:
i. measurement ii. physical quantity iii. mass
iv. regular body V. SI system
vi. CGS system
(b) Name the devices used to measure the volume of liquid.
(c) Define volume. Write its Sl units.
(d) Describe an experiment to find the volume of an irregular stone.
(e) How do you find the volume of a rectangular brick?
(f) SI units are used for scientific works. Why?
(g)
What is area? Write the relation of ma with its multiples.
(h) What is volume? Write the relation of mº with its sub-multiples.
(1) Describe the method of calculation of the area of a rectangular body in short.
0) Write the name of the means used to measure the volume of liquid.
Answers
Answer:
The range of objects and phenomena studied in physics is immense. From the incredibly short lifetime of a nucleus to the age of the Earth, from the tiny sizes of sub-nuclear particles to the vast distance to the edges of the known universe, from the force exerted by a jumping flea to the force between Earth and the Sun, there are enough factors of 10 to challenge the imagination of even the most experienced scientist. Giving numerical values for physical quantities and equations for physical principles allows us to understand nature much more deeply than does qualitative description alone. To comprehend these vast ranges, we must also have accepted units in which to express them. And we shall find that (even in the potentially mundane discussion of meters, kilograms, and seconds) a profound simplicity of nature appears—all physical quantities can be expressed as combinations of only four fundamental physical quantities: length, mass, time, and electric current.
We define a physical quantity either by specifying how it is measured or by stating how it is calculated from other measurements. For example, we define distance and time by specifying methods for measuring them, whereas we define average speed by stating that it is calculated as distance traveled divided by time of travel.
Measurements of physical quantities are expressed in terms of units, which are standardized values. For example, the length of a race, which is a physical quantity, can be expressed in units of meters (for sprinters) or kilometers (for distance runners). Without standardized units, it would be extremely difficult for scientists to express and compare measured values in a meaningful way