mechanics

When are two measurements “same” or “different”? Example of conical shaped pendulums

Student Manual

We have designed a simple experiment using conical shaped pendulums, to see where experiment matches theory. It is customary in practical work to ask when two measurements “match” and when do they “differ”. Furthermore we need to find agreement of experiment with theory. This experiment aims to quantify the similarity (or difference) between various measurements.

Experiment Code1.21
Version2018-v1

Further Readings and References


Pictorial Procedure

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A Doubly Suspended Pendulum

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Student Manual

The objective of this experiment is to determine the moment of inertia of a bi lar pendulum experimentally and then comparing it to the theoretical prediction. The investigation of the bi lar pendulum includes determining the accuracy of the moment of inertia inferred from the experiment and understanding the underlying experimental process.

Sample ResultsA graph showing relationship between time period and inverse of D (distance between the two filars)
Experiment Code1.19
VersionMay 12, 2017

Further Readings and References


Pictorial Procedure

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Vertical pendulum in phase space

Student Manual

A paradigmatic physical system is the physical pendulum is experimentally studied using the acceleration and rotation. A smart phone sensor is used to analyze a vertical pendulum, which is in fact a bicycle wheel. The sensors used in the experiment include the smartphone’s inbuilt gyroscope and accelerometer. Gyroscope is used to measure angular velocity of the wheel while the accelerometer is used to measure the linear acceleration of wheel. A smartphone is fixed to the outside of a bicycle wheel whose axis is kept horizontal and fixed. The compound system, wheel plus smartphone, defines a physical pendulum which can rotate, giving full turns in one direction, or oscillate about its equilibrium position (performing either small or large oscillations). Measurements of the radial and tangential acceleration and the angular velocity obtained with smartphone sensors allows a deep insight into the dynamics of the system.

Sample ResultsPhase space of angular velocity and angular acceleration
Plot of angular velocity vs time
Combined plot of radial acceleration with angular velocity
Experiment Code5.5
Version2016-v1

Further Readings and References

  • Phase space
    Exploring phase space using smartphone acceleration and rotation sensors simultaneously , Martín Monteiro, Cecilia Cabeza and Arturo C Martí , European Journal of Physics, Volume 35 , (2014).

Pictorial Procedure

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Rotational Motion About a Fixed Axis

Student Manual

This task is similar to the experiment “Sliding Friction” where we used the video motion tracking to investigate the friction between the surfaces of a linearly sliding body and a static surface. In this task, we will investigate friction accompanying rotational motion. A disc will be attached to a shaft and manually rotated. Friction will decelerate the rotating disc. We will record this motion on a high speed camera and investigate some interesting aspects of angular kinematics.

Sample ResultsCurve Fitting for Displacement
Curve Fitting for Velocity
Experiment Code5.2A
Version2017-1

Further Readings and References


Pictorial Procedure

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Spring Pendulum

Student Manual

Oscillations are a commonly observed physical phenomenon. In this experiment, we will use our video motion analysis technique to investigate the oscillatory motion of a mass-spring system. We will calculate frequency and damping coefficient of the oscillatory motion.

Sample ResultsCurve Fitting for Vertical Displacement
Curve Fitting for Vertical Velocity
Experiment Code5.4
Version2017-1

Further Readings and References

  • Article 13.1-13.4
    Physics for Scientists and Engineers with Modern Physics , Fishbane, Gasiorowicz and Thornton 366-377 , (1993).

Pictorial Procedure

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Video

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Colliding Pucks on a Carom Board

Student Manual

Collisions are ubiquitous in the nature. They occur at microscopic levels between elementary particles as well as at grander scales when galaxies collide, merge and scatter. In all such processes, the linear momentum of the complete system is always conserved. In this experiment, we will study the collision of two objects in a controlled setup using the video motion tracking technique. We will show that the law of conservation of momentum holds in 2-D collisions and determine the type of collision through quantitative analysis.

Sample ResultsCollision Diagram
Trajectories of the Pucks
Free Body Diagram of the Collsion
Velocity Curve Fitting
Energy Balance
Experiment Code5.3
Version2017-1

Further Readings and References

  • Article 8.1-8.5
    Physics for Scientists and Engineers with Modern Physics , Fishbane, Gasiorowicz and Thornton 209-223 , (1993).

Pictorial Procedure

Puckssetupcarom3carrom2 IMG_1244

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Sliding Friction

Student Manual

Friction is an inevitable phenomenon. Without friction, it would be impossible to walk or drive
cars. However, friction is also the cause of energy loss and we would like to reduce it for higher
efficiency in machines. In this experiment, we will study the force of friction as an object is
stationary and in motion. We will calculate the coefficients of static and sliding friction using
video motion analysis.

Sample ResultsCurve Fitting for Displcement
Experiment Code5.2
Version2017-1

Further Readings and References

  • Article 5.1-5.2
    Physics for Scientists and Engineers with Modern Physics , Fishbane, Gasiorowicz and Thornton 119-133 , (1993).

Pictorial Procedure

The setup used for the experimentIMG_1231 IMG_1232 IMG_1233

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Projectile Motion

Student Manual

The purpose of this lab is to study the motion of a projectile launched using a projectile launcher
and inspect different aspects of projectile motion using high speed video processing.

Sample ResultsTrajectory of the Projectile
Curve Fitting for Vertical Velocty
Visualisation of the Trajectory of the Projectile
Total Energy
Time vs Height
Experiment Code5.1
Version2017-1

Further Readings and References

  • Article 3.1-3.4
    Physics for Scientists and Engineers with Modern Physics , Fishbane, Gasiorowicz and Thornton , 1 60-73 , (1993).

Pictorial Procedure

The experimental setup

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