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Grade 6Mechanics

T=Kmx Ly gz , find x,y,z and derive the expression for period(T) of ossillation

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4 Years agoGrade 6
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ApprovedApproved Tutor Answer1 Year ago

To derive the expression for the period (T) of oscillation from the equation T = Km x L^y g^z, we need to identify the dimensions of each variable and apply dimensional analysis. This approach will help us find the values of x, y, and z. Let's break it down step by step.

Understanding the Variables

In the equation T = Km x L^y g^z:

  • T is the period of oscillation, measured in seconds (s).
  • K is a dimensionless constant.
  • L represents a length, measured in meters (m).
  • g is the acceleration due to gravity, measured in meters per second squared (m/s²).

Dimensional Analysis

To find the values of x, y, and z, we need to express the dimensions of T in terms of L and g. The dimensional formula for T is:

  • [T] = [M^0 L^0 T^1] = T

Next, we express L and g in terms of their dimensions:

  • [L] = [M^0 L^1 T^0] = L
  • [g] = [M^0 L^1 T^-2] = L T^-2

Setting Up the Equation

Now, substituting the dimensions of L and g into the equation T = Km x L^y g^z gives us:

[T] = [L^y] [g^z] = [L^y] [L^z T^-2z]

This simplifies to:

[T] = [L^(y+z) T^(-2z)]

Equating Dimensions

For the dimensions to be consistent, we must have:

  • For length: y + z = 0
  • For time: -2z = 1

Solving the Equations

From the second equation, we can solve for z:

-2z = 1 ⟹ z = -1/2

Now, substituting z into the first equation:

y + (-1/2) = 0 ⟹ y = 1/2

Finding x

Since K is a dimensionless constant, x does not affect the dimensional analysis. Therefore, we can conclude that:

  • x = 0 (as it does not contribute to the dimensions).

Final Expression for the Period T

Now that we have determined the values of x, y, and z, we can rewrite the expression for the period of oscillation:

T = K * L^(1/2) * g^(-1/2)

This can also be expressed as:

T = K * sqrt(L/g)

Conclusion

In summary, we found that x = 0, y = 1/2, and z = -1/2. The derived expression for the period of oscillation is T = K * sqrt(L/g). This relationship shows how the period of oscillation depends on the length of the pendulum and the acceleration due to gravity, which is fundamental in understanding simple harmonic motion.