Gravitational Constant Viva Prep

What is the gravitational constant (G) and why is it significant in physics?,

The gravitational constant is a fundamental physical constant that quantifies the strength of the gravitational force between two masses. Its value is approximately 6.674 × 10^-11 N·m²/kg². G is crucial in Newton's law of universal gravitation which describes the attractive force between any two masses. ,

How is the acceleration due to gravity (g) defined and what is its typical value on Earth?,

The acceleration due to gravity is the acceleration experienced by an object due to Earth's gravitational pull. Its standard value at Earth's surface is approximately 9.81 m/s². ,

What are the four primary methods for measuring the acceleration due to gravity (g)? ,

The four primary methods are: 1. End-deflection method using a laser 2. End-deflection method using infrared (IR) sensors 3. Acceleration method using a laser 4. Acceleration method using infrared (IR) sensors. ,

What is the end-deflection method in measuring gravity? ,

The end-deflection method involves measuring the angular displacement of a torsion balance when masses are positioned to exert gravitational forces causing the system to deflect. The deflection is proportional to the gravitational force allowing calculation of G. ,

How does the acceleration method differ from the end-deflection method in measuring gravity? ,

The acceleration method measures the time it takes for an object to fall a known distance using sensors like lasers or IR to detect motion. By applying kinematic equations the acceleration due to gravity (g) can be calculated. ,

What equipment is used in the end-deflection method with a laser? ,

The setup includes a torsion balance with small masses attached to a rod suspended by a thin wire. large stationary masses induce gravitational attraction. a laser pointer is directed at a mirror on the rod. and a scale to measure the laser's deflection on a distant wall. ,

How is infrared technology utilized in the end-deflection method? ,

Infrared sensors detect the position of the torsion balance without visible light interference. IR detectors measure the angular displacement by detecting changes in IR beam position reflected from the torsion balance. ,

What is the role of infrared sensors in the acceleration method?

, Infrared sensors detect the passage of a falling object by emitting and receiving IR beams. When the object interrupts the beam the sensor records the time which is used to calculate the acceleration due to gravity. ,

Compare the accuracy and time efficiency of the end-deflection and acceleration methods.

, The end-deflection method offers higher accuracy (within 10%) but requires longer observation times (up to 45 minutes). The acceleration method is quicker (about 5 minutes) but has slightly lower accuracy (within 15%). ,

What are the advantages of using lasers over infrared sensors in these experiments?

, Lasers provide precise and focused beams allowing for accurate detection of small deflections or time intervals. They are less susceptible to ambient light interference compared to IR sensors as IR sensors can be affected by environmental IR sources. ,

In what scenarios might infrared sensors be preferred over lasers? ,

Infrared sensors are beneficial in setups where visible light might interfere with measurements or when a non-visible detection method is required. They are also generally more cost-effective and easier to integrate into certain experimental designs. ,

What are common sources of uncertainty in the end-deflection method?

, Uncertainties arise from air currents affecting the torsion balance. imperfections in the suspension wire. measurement errors in detecting angular displacement. and external vibrations. ,

How can uncertainties in the acceleration method be minimized?

, Using precise timing devices ensuring the object falls vertically without air resistance (e.g. in a vacuum) calibrating sensors accurately and repeating measurements to average out anomalies can reduce uncertainties. ,

Why is it important to consider both accuracy and efficiency when choosing a method to measure gravity?

, Balancing accuracy and efficiency ensures reliable results within practical time frames. High accuracy is essential for precise measurements while efficiency allows for more experiments to be conducted in less time therefore facilitating better data collection and analysis.