Q1: Define Mechanics.
Ans: Mechanics is the branch of physics that deals with the study of forces and motion of bodies.
Q2: Define Applied Mechanics.
Ans: Applied mechanics is the practical application of mechanics to solve engineering problems.
Q3: Define Units.
Ans: Units are standard quantities used to measure physical quantities.
Q4: Define Derived Units. Name some.
Ans: Derived units are units obtained from fundamental units.
Examples are:
- ➔ Velocity (m/s)
- ➔ Force (N)
- ➔ Work (J)
- ➔ Pressure (Pa)
Q5: Define Fundamental Units. Name some.
Ans: Fundamental units are basic units that cannot be derived from other units.
Examples are:
- ➔ Meter (m)
- ➔ Kilogram (kg)
- ➔ Second (s)
Q6: Define Basic Units. Name some.
Ans: Basic units are same as fundamental units used to measure basic physical quantities.
Examples are:
- ➔ Length (meter)
- ➔ Mass (kilogram)
- ➔ Time (second)
Q7: Define measurement.
Ans: Measurement is the process of comparing an unknown quantity with a standard unit.
Q8: State the units of measurements.
Ans: Units of measurement include:
- ➔ Length → meter (m)
- ➔ Mass → kilogram (kg)
- ➔ Time → second (s)
Q9: What is the M.K.S system?
Ans: M.K.S system uses meter, kilogram, and second as base units.
Q10: What is the F.P.S system?
Ans: F.P.S system uses foot, pound, and second as base units.
Q11: What is the C.G.S system?
Ans: C.G.S system uses centimeter, gram, and second as base units.
Q12: What is the S.I system?
Ans: S.I system is the international system of units used worldwide.
It includes meter, kilogram, and second as basic units.
Q13: Convert 2 Miles into Meters.
Ans: 1 mile = 1609 m
2 miles = 2 × 1609 = 3218 m
Final Answer:
2 miles = 3218 m
Q14: Convert 500 ft into inches.
Ans: 1 ft = 12 inches
500 ft = 500 × 12 = 6000 inches
Final Answer:
6000 inches
Q15: The speed of a cycle is 4ft/s. Find the speed in m/s
Ans: 1 ft = 0.3048 m
Speed = 4 × 0.3048 = 1.219 m/s
Final Answer:
1.22 m/s
Q16: Define velocity. Write its formula.
Ans: Velocity is the rate of change of displacement with time and has direction.
Formula:
Velocity = Displacement / Time
Q17: Define Density. Write its formula.
Ans: Density is the mass per unit volume of a substance.
Formula:
Density = Mass / Volume
Q18: What is Dimensional Equation?
Ans: A dimensional equation shows the relationship between physical quantities in terms of fundamental units like M, L, and T.
Q19: State the uses of Dimensional Equations.
Ans: Uses are:
- ➔ To check correctness of equations
- ➔ To convert units
- ➔ To derive formulas
Q20: Express a speed of 50km/hr as m/s.
Ans: 1 km/hr = 5/18 m/s
50 × (5/18) = 250/18 = 13.89 m/s
Final Answer:
13.89 m/s
Q21: Define Significant Figures. State some examples.
Ans: Significant figures are digits in a number that carry meaningful information about precision.
Examples:
- ➔ 25.3 (3 significant figures)
- ➔ 0.0045 (2 significant figures)
- ➔ 100.5 (4 significant figures)
Q22: State the rules for identifying significant figures.
Ans: Rules are:
- ➔ All non-zero digits are significant
- ➔ Zeros between digits are significant
- ➔ Leading zeros are not significant
- ➔ Trailing zeros after decimal are significant
Q23: State the difference between Precision and Accuracy.
Ans: Precision means how close repeated values are to each other.
Accuracy means how close a value is to the true value.
Q24: Define Relative Error.
Ans: Relative error is the ratio of absolute error to true value.
Formula:
Relative Error = Absolute Error / True Value
Q25: Prove that 1N = 10⁵ dyne.
Ans: 1 N = 1 kg·m/s2
1 kg = 1000 g
1 m = 100 cm
So,
1 N = 1000 × 100 g·cm/s2
1 N = 100000 dyne = 105 dyne
Q26: Convert 5 Horse Power into Watt.
Ans: 1 HP = 746 W
5 × 746 = 3730 W
Final Answer:
3730 W
Q27: The density of water is 1g/cm3. express it in kg/m3.
Ans: 1 g = 0.001 kg
1 cm3 = 10-6 m3
Density = 0.001 / 10-6 = 1000 kg/m3
Final Answer:
1000 kg/m3
Q28: Convert 5 hours 30 minutes into seconds.
Ans: 5 hours = 5 × 3600 = 18000 s
30 minutes = 30 × 60 = 1800 s
Total = 18000 + 1800 = 19800 s
Final Answer:
19800 seconds
Q29: The height of the student is 5ft 9inches. Convert it into meters.
Ans: 1 ft = 0.3048 m
1 inch = 0.0254 m
5 ft = 5 × 0.3048 = 1.524 m
9 inch = 9 × 0.0254 = 0.2286 m
Total height = 1.524 + 0.2286 = 1.7526 m
Final Answer:
1.75 m
Q30: What is the density of water?
Ans: The density of water is:
1000 kg/m3 or 1 g/cm3
