A student group designs an experiment to measure the angular acceleration of a smooth
PHYSICS · Multi-part · CBSE · Physics · System of Particles and Rotational Motion · System of Particles and Rotational Motion
Problem
A student group designs an experiment to measure the angular acceleration of a smooth, horizontal rotating platform. They attach two identical small blocks of putty to the platform at radial distances r1 and r2 (with r2>r1). The platform is allowed to start from rest and speed up under a small, constant external torque. A motion sensor records the tangential (linear) acceleration of each block as the platform speeds up.
(1) Part 1: Starting from appropriate definitions, derive an expression for the platform’s angular acceleration α in terms of the measured tangential acceleration at and the radial distance r of any point on the platform.
(2) Part 2: Explain how simultaneous measurements of at1 at r1 and at2 at r2 can be used to confirm that the platform behaves as a rigid body undergoing constant angular acceleration.
(3) Part 3: Outline a detailed experimental procedure—specifying the measurements to be taken and how the data will be analyzed—to obtain a single best estimate of α from the two putty blocks’ data.
(4) Part 4: Identify two significant sources of experimental uncertainty or systematic error in this procedure and describe how each could affect the calculated value of α.