Concepts Of Physics MCQ Edition [Volume 1]PhysicsIntroduction to Physics
Determine if the following equation is dimensionally correct: h = 2 S r g where h = height, S = surface tension, = density, P = pressure, V = volume, = coefficient of viscosity, = frequency and I = moment of inertia.
Options
- AThe equation is dimensionally incorrect, as the right side has dimensions of [L^2] .
- BThe equation is dimensionally incorrect, as the right side has dimensions of [L⁻¹] .
- CThe equation is dimensionally incorrect, as the right side has dimensions of [M L T⁻²] .
- DThe equation is dimensionally correct.
Correct answer
D. The equation is dimensionally correct.
Step-by-step solution
Dimensions of the left-hand side: [h] = [L] Dimensions of the quantities on the right-hand side: [S] = [M T⁻²] [ ] = [M^0 L^0 T^0] [ ] = [M L⁻³] [r] = [L] [g] = [L T⁻²] Substituting these dimensions into the right-hand side: RHS = [M T⁻²] [M L⁻³] [L] [L T⁻²] RHS = [M T⁻²] [M L⁻¹ T⁻²] RHS = [L] Since the dimensions of the left-hand side equal the dimensions of the right-hand side, the equation is dimensionally correct.