Question

A particle of mass m slides along curved − flat − curved track. The curved portions of the track are smooth. If the particle is released at the top of one of the curved portions the particle comes to rest at flat portion of length l and of coefficient of kinetic friction = μ_kinetic after covering length of

• A. l/3μ_kinetic
• B. H/2μ_kinetic
• C. l/6
• D. H/μ_kinetic

Answer 1

Answer: (D)

H/μ_kinetic

Answer 2

use P.E. = Work done

mgH = μ_kinetic mgS

or S = $\frac { \mathrm { H } } { \mu _ { \text {kinetic } } }$

The particle covers the length l or not, or covers it repeatedly is determined by the above relation.