When a box of mass 45kg is given an initial speed of 5m/s, it slides along a horizontal floor a distance of 3m before coming to rest. What is the coefficient of the kinetic friction between the box and the floor?

John Perolski
September 03, 2023

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QUESTIONS 10: When a box of mass 45kg is given an initial speed of 5m/s, it slides along a horizontal floor a distance of 3m before coming to rest. What is the coefficient of the kinetic friction between the box and the floor? g =10m/s²

Ans: 0.417 or 5/12 JAMB 1986

SOLUTIONS 

coefficient of friction μ =F/R

F=ma

v²=u²+2as

0=5²+2×a×3

25=6a

a=25/6

a=4.167

F=45×4.167

F=187.5

R=45×10=450

coefficient of friction μ, =187.5/450

μ = 0.4167

Or

μ = 5/12 Answer