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Solve the simplified form, the period of vibration p for a pendulum varies directly as the square root of its length l. if p is 2.5 sec. when l is 25 in., what is the period when the length is 49 in.?group of answer choices

O 24.5 sec
O 98 sec
O 3.5 sec
O 14 sec

2 Answers

2 votes

The period when the length is 49 in. is 3.5 seconds. So, the correct answer is C:


\[ \text{Period} = 3.5 \, \text{sec} \]

The relationship between the period
(\(p\)) of a pendulum and its length
(\(l\)) is given as:


\[ p \propto √(l) \]

This can be written as an equation with a constant of proportionality
(\(k\)):


\[ p = k √(l) \]

To find
\(k\), use the initial values where
\(p\) is 2.5 sec. when
\(l\) is 25 in.:


\[ 2.5 = k √(25) \]

Solve for
\(k\):


\[ k = (2.5)/(√(25)) = (2.5)/(5) = 0.5 \]

Now that you have
\(k\), you can use it to find the period
(\(p'\)) when the length
(\(l'\)) is 49 in.:


\[ p' = 0.5 √(49) \]


\[ p' = 0.5 * 7 = 3.5 \, \text{sec} \]

Therefore, the period when the length is 49 in. is 3.5 seconds. So, the correct answer is C:


\[ \text{Period} = 3.5 \, \text{sec} \]

User Ignis
by
7.6k points
5 votes

Final answer:

To find the new period when the length of the pendulum is 49 inches, we use the ratio of the given period and length and find that the period p is 3.5 seconds.The correct option is option c .

Step-by-step explanation:

The period of vibration p for a pendulum varies directly as the square root of its length l. We are given that when p is 2.5 seconds, l is 25 inches. To find out the period when the length is 49 inches, we use the direct variation relationship between p and the square root of l. The formula for the period of a simple pendulum is T = 2π√(l/g), where g is the acceleration due to gravity and doesn't change with the pendulum's length or mass. Since g remains constant and was not provided, we don't need its value to calculate the new period; we can use ratios instead:

  • p₁/√l₁ = p₂/√l₂
  • 2.5/√25 = p₂/√49
  • p₂ = 2.5 * √49 / √25
  • p₂ = 2.5 * 7 / 5
  • p₂ = 3.5 seconds

Therefore, when the length of the pendulum is 49 inches, the period p is 3.5 seconds.

User XPheRe
by
7.7k points