CARA MENGHITUNG FREKUENSI DAN PERIODE GETARAN | IPA KELAS 8 SMP SEMESTER 2

Summary

This educational video for class 8 students focuses on calculating the frequency and period of oscillatory motions. It explains the essential formulas, such as frequency (f = n/t) and period (T = 1/f), with clear examples using simple objects like pendulums and tuning forks. The instructor demonstrates step-by-step how to calculate both frequency and period for various scenarios, including converting units and simplifying calculations. The video aims to make learning these concepts easy and accessible for students, reinforcing key points with practical examples and encouraging active participation in solving problems.

Takeaways

• 😀 The formula for frequency is f = n/t, where 'n' is the number of vibrations and 't' is the time period.
• 😀 To calculate the frequency, if only the period (t) is known, use the formula f = 1/t.
• 😀 When calculating frequency from a given period, first remove decimal places by multiplying both the numerator and denominator by 10 for simplicity.
• 😀 To find the period from frequency, use the formula t = 1/f.
• 😀 The unit for frequency is Hertz (Hz), and the unit for the period is seconds (s).
• 😀 In practical calculations, rounding or adjusting decimal points may be necessary for easier computation.
• 😀 When the number of vibrations and time are known, the frequency can be calculated by dividing the number of vibrations by the time.
• 😀 To find the period, one can use either the formula t = t/n or t = 1/f, depending on the known quantities.
• 😀 The example of a pendulum with a period of 0.2 seconds illustrates how to calculate the frequency by using f = 1/t.
• 😀 For problems involving the number of vibrations and time, such as a tuning fork vibrating 100 times in 4 seconds, the frequency can be determined using n/t and the period can be calculated using 1/f.

Q & A

What is the formula for calculating frequency?

The formula for frequency is f = n / t, where 'f' represents the frequency, 'n' is the number of vibrations or oscillations, and 't' is the period.

How can we calculate the period when only the frequency is known?

The period can be calculated using the formula t = 1 / f, where 't' is the period and 'f' is the frequency.

In the first problem, how do we calculate the frequency of a pendulum with a period of 0.2 seconds?

To calculate the frequency, use the formula f = 1 / t. For a period of 0.2 seconds, f = 1 / 0.2, which simplifies to 5 Hz.

How do we calculate the frequency of a tuning fork that vibrates 100 times in 4 seconds?

To calculate the frequency, use the formula f = n / t. Here, n = 100 (the number of vibrations) and t = 4 seconds, so f = 100 / 4 = 25 Hz.

What is the period of a tuning fork that vibrates 100 times in 4 seconds?

The period can be calculated by using the formula t = 1 / f. Given that the frequency is 25 Hz, the period is t = 1 / 25, which equals 0.04 seconds.

How do we calculate the frequency and period for an object that vibrates 1200 times in 2 minutes?

First, convert the time to seconds (2 minutes = 120 seconds). Then, to calculate the frequency, use f = n / t. With n = 1200 and t = 120, the frequency is f = 1200 / 120 = 10 Hz. The period is t = 1 / f = 1 / 10 = 0.1 seconds.

What is the frequency of an object with a period of 5 seconds?

To find the frequency, use the formula f = 1 / t. Given the period is 5 seconds, the frequency is f = 1 / 5 = 0.2 Hz.

How do you find the number of vibrations in 0.5 seconds for an object with a frequency of 100 Hz?

To calculate the number of vibrations, use the formula n = f * t. With a frequency of 100 Hz and time of 0.5 seconds, n = 100 * 0.5 = 50 vibrations.

What is the period of an object with a frequency of 100 Hz?

The period can be found using the formula t = 1 / f. With a frequency of 100 Hz, the period is t = 1 / 100 = 0.01 seconds.

What does the term 'period' refer to in the context of vibrations?

The period refers to the amount of time it takes for one complete vibration or oscillation to occur. It is measured in seconds.