Per NCERT Example 5.4, a bullet of mass 50 g at 200 m/s emerges from plywood with 10% of initial KE. The emergent speed is closest to which value?
A63.2 m/s
B20 m/s
C6.3 m/s
D100 m/s
Answer & Solution
Correct answer: A. 63.2 m/s
NCERT Ex 5.4: K_i = (1/2)(0.05)(200)² = 1000 J. K_f = 100 J ⇒ v_f = √(2 K_f/m) = √(4000) ≈ 63.2 m/s.
Related questions
A crate dragged across a rough floor loses mechanical energy because friction is:Conservation of mechanical energy is the form the work-energy theorem takes when the forceCalculating work for a conservative force is easier than for a complicated path because itA force acting entirely perpendicular to an object's displacement does how much work?Mechanical energy transferred into or out of a system equals the work done by an external Winding up a toy or an old-fashioned watch stores energy by doing work against its:Which three energy examples are named together?The kinetic energy in the work-energy theorem is specifically the translational kinetic en