a simple pendulum has a period of 4.2 s. when it is shortened by 1.0 m the period is only 3.7 s.

A. without assuming a value for g , calculate the original length of the pendulum

T =2 pi sqrt(L/g) = k sqrt L where k is a constant (on earth)

k sqrt L = 4.2
k sqt (L-1) = 3.7

k^2 L = 17.64
k^2 (L -1) = 13.69

k^2 L / k^2(L-1) = 17.62/13.69
L/(L-1) = 1.287
L = 1.387 L - 1.287
0.387 L = 1.287

To calculate the original length of the pendulum without assuming a value for g, we can use the formula for the period of a simple pendulum.

The formula for the period of a simple pendulum is:

T = 2π * √(L/g)

where T is the period, L is the length of the pendulum, and g is the acceleration due to gravity.

We are given that the initial period, T1, is 4.2 seconds and the shortened period, T2, is 3.7 seconds. We can set up the following equations:

T1 = 2π * √(L1/g)
T2 = 2π * √(L2/g)

Squaring both equations, we get:

T1^2 = 4π^2 * (L1/g)
T2^2 = 4π^2 * (L2/g)

Dividing the second equation by the first equation, we get:

(T2^2) / (T1^2) = (L2/L1)

Substituting the given values, we have:

(3.7^2) / (4.2^2) = (L2/L1)

Simplifying the equation, we find:

0.869 = (L2/L1)

Therefore, the original length L1 of the pendulum can be calculated by multiplying the shortened length L2 by 0.869.

L1 = L2 * 0.869

Substituting the given shortened length L2 (which is shortened by 1.0 m), we can finally calculate the original length of the pendulum:

L1 = (L2 - 1.0) * 0.869