Straight-line graphs of kinetic energy K versus the square of speed v² are obtained…

PHYSICS · Multi-part · CBSE · Physics · Work, Energy and Power · Work, Energy and Power

Problem

Straight-line graphs of kinetic energy K versus the square of speed v² are obtained for two bodies X and Y moving on a frictionless surface. Both lines pass through the origin. The slope of the line for X is 2.8 J·s² m⁻², whereas that for Y is 4.0 J·s² m⁻². Answer the following questions. (i) Derive an expression relating the slope of a K–v² graph to the mass of the body. (ii) Calculate the masses of bodies X and Y. (iii) Find the kinetic energy of each body when its speed is 6 m/s. (iv) At what speed will the kinetic energies of X and Y differ by 30 J?

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