What is the effect on the period of a pendulum if you decrease its length by 7.85%? (Answer this question in terms of the initial period T.)

0.955T

Explanation:

The effect on the period in case when there is a decrease in length by 7.85%

Let us assume the following items

Period = T

T= Beginning period

L = Beginning length

T' = Final period

L' = Final length

Based on the above information

As we know that

Therefore

Hence, the effect on the period is 0.955T

you'd use the equation that establishes a relationship between  energy  and  wavelength, which looks like this

e=h⋅cλ, where

λ  - the wavelength of the photon; c  - the speed of light, usually given as  3⋅108m/s; h  -  planck's constant, equal to  6.626⋅10−34j s

plug the value you were given for the energy of the photon in the above equation to get the wavelength

e=h⋅cλ⇒λ=h⋅ce

λ=6.626⋅10−34js⋅3⋅108ms−1.257⋅10−24j=1.581⋅10−1m