Question

A cylinder of radius $5m$ rolls on a horizontal surface. Velocity of its center is $25m/s$. Find velocity of the point $A$

• A. $(40\hat{i}-20\hat{j})m/s$
• B. $(20\hat{i}+40\hat{j})m/s$
• C. $(40\hat{i}+20\hat{j})m/s$
• D. $(20\hat{i}+20\hat{j})m/s$

Answer 1

Answer: (C)

Velocity of the point A can be calculated by either analytical method, superposition method or by using method of ICR
Analytical Method:
$\overrightarrow{v_A}=\overrightarrow{v_c}+\vec{\omega }\times \overrightarrow{CA}\to$
$\overrightarrow{v_A}=25\hat{i}+(-5\hat{k})\times \left(-5\cos 37^0\hat{i}+5\sin 37^0\hat{j}\right)$
$\overrightarrow{v_A}=(40\hat{i}+20\hat{j})m/s$