MI1 - MOMEN INERSIA 1

Summary

In this practical session on the 'Moment of Inertia,' the presenter Meliana introduces the concept of rotational motion and its key components, such as torque and moment of inertia. The session includes two experiments: one to determine the spring constant using a spiral spring, and another to measure the moment of inertia of an object. Safety protocols are emphasized, and the process involves careful setup of equipment, accurate data collection, and precise measurement of displacements and periods. The session concludes with a promise of further analysis in the next week’s practical session.

Takeaways

• 😀 The session introduces the concept of 'momen inersia' (moment of inertia) and provides a detailed explanation of its theoretical foundation.
• 😀 'Momen gaya' (torque) is explained as a vector quantity causing rotational motion about a specific axis, with the formula to = r * f * sin(θ).
• 😀 Moment of inertia measures the resistance of an object to rotational motion and is calculated as the mass of the object multiplied by the square of the distance from the axis.
• 😀 The relationship between torque and moment of inertia is discussed, including the formula to = I * α (torque equals moment of inertia times angular acceleration).
• 😀 The first experiment focuses on determining the spring constant (K) using a spiral spring and various weights. Observations include measuring angular displacement.
• 😀 Experiment 1 involves five data points with different masses to observe displacement, with each data point taken multiple times for accuracy.
• 😀 The second experiment aims to determine the moment of inertia of an apparatus using a light gate sensor and a timer-counter setup to measure the period of oscillation.
• 😀 The data collection for Experiment 2 involves measuring five periods of oscillation and recording the corresponding times for each period.
• 😀 The video emphasizes safety protocols, such as avoiding damage to the equipment, ensuring proper positioning of the apparatus, and handling the apparatus carefully during the experiment.
• 😀 The script outlines the necessary tools and materials for each experiment, including inertia apparatus, various masses, and sensors, alongside step-by-step procedures for setting up and conducting the experiments.

Q & A

What is the primary focus of the practical module in the video?

The primary focus of the practical module is to understand and measure the moment of inertia through experiments involving a spring constant and the inertia of a rotating object.

What is torque and how is it calculated?

Torque, or torka, is the rotational equivalent of force, causing an object to rotate around a specific axis. It can be calculated using the formula τ = r * F * sin(θ), where 'r' is the distance from the axis of rotation, 'F' is the applied force, and 'θ' is the angle between the force and the lever arm.

What is moment of inertia and how is it defined in the script?

Moment of inertia is defined as the measure of an object's resistance to rotational motion around a specific axis. It is calculated as the mass of an object multiplied by the square of its distance from the axis of rotation.

How does the experiment determine the spring constant?

In the first experiment, the spring constant is determined by observing the angular displacement when different weights are attached to the apparatus. The torque is proportional to the displacement, which allows for the calculation of the spring constant.

What is the role of the light gate and counter in the second experiment?

The light gate and counter are used in the second experiment to measure the period of oscillation. The light gate detects the passing of the rotating object, while the counter records the time intervals for calculating the moment of inertia.

What is the significance of the angle (θ) in the torque formula?

The angle (θ) in the torque formula represents the angle between the force vector and the lever arm. It affects the magnitude of the torque since torque is maximal when the force is applied perpendicular to the lever arm (θ = 90°).

What precautions are mentioned to ensure safety during the experiment?

The script emphasizes several safety precautions, including handling the equipment carefully, ensuring that the apparatus is not damaged during setup, and using the correct rotational direction to prevent damage. Also, participants are advised not to force the equipment and to ensure that sensors are correctly positioned.

How are the data for the period of oscillation collected in the second experiment?

The data for the period of oscillation are collected using a timer and counter, with five measurements taken for each period of oscillation. The timer records the time for each cycle, which is then used to calculate the moment of inertia.

What is the formula for calculating the period of oscillation and moment of inertia in this experiment?

The period of oscillation is given by the formula T = 2π * √(I / k), where 'I' is the moment of inertia and 'k' is the spring constant. From the period data, the moment of inertia can be calculated using this relation.

How does the mass of the object affect the moment of inertia in the experiments?

In the experiments, the mass of the object affects its moment of inertia because moment of inertia is directly proportional to the mass and the square of the distance from the axis of rotation. Increasing the mass or changing the position of the mass will affect the rotational inertia.