A student writes the following entry in the laboratory notebook: "The second hand of…
PHYSICS · Multi-part · CBSE · Physics · System of Particles and Rotational Motion · System of Particles and Rotational Motion
Problem
A student writes the following entry in the laboratory notebook:
"The second hand of a wall clock, having length 10 cm, moves through an angle of 90 cm in 15 s. Therefore, the angular displacement is 90 cm and the arc length is 90 rad."
Answer the questions based on this record:
(i) Identify and explain all errors in the quoted statement, paying special attention to the misuse of units and symbols.
(ii) Calculate the correct angular displacement (in radians) of the second hand in 15s.
(iii) Using the correct value from part (ii), determine the actual arc length travelled by the tip of the second hand. State the answer with proper units.