A bullet of mass a traveling with speed b embeds into a stationary wooden block of mass c. If final common speed is n·ab/(a+c), find n.
Physics · Mixed Chapter
JEE Main Practice

Question

A bullet of mass a traveling with speed b embeds into a stationary wooden block of mass c. If final common speed is n·ab/(a+c), find n.

G1 Physics · Accepted Answer

Step 1: Before impact total momentum is ab. Step 2: After perfectly inelastic impact total mass is a+c and common speed v. Step 3: Momentum conservation gives ab=(a+c)v⇒v=ab/(a+c). Thus n=1.