A small electric car travels around a level circular test track of radius
PHYSICS · Multi-part · CBSE · Physics · Motion in a Plane · Motion in a Plane
Problem
A small electric car travels around a level circular test track of radius 50m. A data-acquisition system measures the car’s instantaneous speed v and the corresponding magnitude of its acceleration ac directed toward the track’s center. The student plans to construct two separate graphs from the same set of measurements:
• graph 1: ac on the vertical axis versus v on the horizontal axis
• graph 2: ac on the vertical axis versus v2 on the horizontal axis
Assume the car’s motion remains uniform and the tyres do not skid.
(a) Describe qualitatively the shape and intercept of graph 1 that the student should expect. Justify your answer without performing a numerical calculation.
(b) Explain why plotting ac versus v2 (graph 2) instead of v is advantageous for analyzing the data. In your explanation, write the mathematical relationship between ac and v2 and identify the physical meaning of the slope.
(c) Suppose the best-fit line for graph 2 yields a slope of 0.020m−1. Interpret the numerical value and units of this slope in the context of the experiment, and state whether the track radius determined from the graph is consistent with the manufacturer’s quoted value of 50m. Support your conclusion with reasoning.