Chapter 1 Flashcards
(21 cards)
What are the two types of physical quantities?
Physical quantities are classified into two types: Fundamental Quantities and Derived Quantities.
What are fundamental quantities?
Fundamental quantities are those that cannot be expressed in terms of any other physical quantities. They include length, mass, time, electric current, temperature, luminous intensity, and amount of substance.
What are derived quantities?
Derived quantities are those that can be expressed in terms of fundamental quantities. Examples include area, volume, velocity, acceleration, and force.
What are the rules for counting significant figures?
- All non-zero digits are significant.
- All zeros between two non-zero digits are significant.
- All zeros to the right of a decimal point and to the right of a non-zero digit are significant.
- All zeros to the right of a non-zero digit but to the left of a decimal point are not significant if the number has no decimal point.
How do you measure the diameter of the Moon using the parallax method?
Once the distance ‘D’ of a planet is determined, the diameter ‘d’ can be estimated by measuring the angle ‘α’ between two diametrically opposite points M and N of the moon viewed from a point A on Earth. The formula is d = αD.
What are the limitations of dimensional analysis?
- It gives no information about dimensionless constants in formulas.
- It cannot determine if a quantity is a vector or scalar.
- It is not suitable for deriving relationships involving trigonometric, exponential, and logarithmic functions.
How many significant figures are in the number 0.00345?
The number 0.00345 has three significant figures.
How many significant figures are in the number 1342?
The number 1342 has four significant figures.
How many significant figures are in the number 2008?
The number 2008 has four significant figures.
How many significant figures are in the number 30700?
The number 30700 has three significant figures, but 30700. has five significant figures.
How many significant figures are in the number 40.00?
The number 40.00 has four significant figures.
How many significant figures are in the number 0.030400?
The number 0.030400 has five significant figures.
What is an example of a number with three significant figures?
Examples include 1.53 cm, 0.0153 m, and 0.0000153 km.
What is a screw gauge?
A screw gauge is an instrument used for measuring the dimensions of an object, specifically for small distances.
What is a vernier caliper?
A vernier caliper is a versatile instrument used for measuring small distances.
What are the methods to measure larger distances?
The triangulation method and radar method are used to measure larger distances.
What is the difference between precision and accuracy?
Precision is a measure of the consistency of measurements, while accuracy is a measure of the closeness of the measured value to the true value.
Can a measurement be precise but not accurate?
Yes, a measurement can be precise (consistent) but not accurate (close to the true value).
What does the precision of an instrument indicate?
The precision of an instrument gives the minimum value that can be measured.
What is an example of precision and accuracy?
If the temperature of a refrigerator is repeatedly measured as 10.4°C, 10.2°C, 10.3°C, 10.1°C, 10.2°C, 10.1°C, 10.1°C, 10.1°C, it shows precision. However, if the true temperature is 9°C, it indicates inaccuracy.
What is the correct relation in dimensional analysis?
The correct relation is s = ut + (1/2)at², which checks the dimensional correctness.
