A physicist uses dimensional analysis to derive an expression for the energy (E) of a particle based on its mass (m), velocity (v), and Planck's constant (h). They arrive at . Why is this result incomplete?
Dimensional analysis cannot account for dimensionless quantities like the fine-structure constant, which might be involved in a more complex relationship.
Planck's constant is not relevant for the energy of a classical particle, invalidating the analysis.
Dimensional analysis cannot handle situations involving both mass and velocity.
The correct expression involves a logarithmic relationship, which dimensional analysis cannot capture.
Related Questions
Which of the following cannot be determined using dimensional analysis?
Numerical value of a constant
Units of a physical quantity
Conversion of units
Consistency of a physical equation
The vernier scale of a vernier callipers has divisions that coincide with divisions on the main scale. If the main scale is marked in millimeters, what is the least count of the instrument (in cm)?
In a vernier callipers, divisions of vernier scale coincide with divisions of the main scale. If 1 MSD represents mm, the vernier constant (in cm) is:
In a vernier callipers, divisions on the vernier scale coincide with divisions on the main scale. If each division on the main scale is mm, find the vernier constant (in cm).
Dimensional analysis can help in deriving relationships between physical quantities. However, it cannot:
Check the homogeneity of physical equations
Convert units from one system to another
Deduce the dimensions of a physical quantity
Distinguish between two physical quantities having the same dimensions
Dimensional analysis can be used to check the correctness of an equation. However, it fails to identify the presence of:
Variables with same dimensions
Dimensionless constants
Trigonometric functions
Logarithmic functions
Dimensional analysis is used to check the validity of an equation relating the speed of sound (v) in a gas to its pressure (P) and density (). Which limitation prevents dimensional analysis from distinguishing between and ?
It cannot determine dimensionless constants.
It cannot handle fractional exponents.
It assumes a linear relationship between variables.
It fails when more than three variables are involved.
Dimensional analysis fails to determine the formula for a physical quantity if it depends on:
Only one physical quantity
Two physical quantities
Three physical quantities
More than three physical quantities
A student uses dimensional analysis to analyze the time () it takes for a capacitor (C) to discharge through a resistor (R). They correctly identify that depends on R and C. However, they are unable to derive the precise relationship . What limitation of dimensional analysis explains this?
Dimensional analysis cannot reveal purely numerical relationships between variables.
The analysis requires knowledge of the initial charge on the capacitor, which is not provided.
Dimensional analysis cannot handle exponential decay processes.
The relationship between , R, and C is logarithmic, not a power law.