Answer:
0.298
Explanation:
Work equals change in energy. So the work done by friction equals the final kinetic energy minus the initial potential energy.
W = ΔE
Fd = ½ mv² − mgh
Nμ (-d) = 46.0 J − (25 N) (3.30 m)
-Nμ d = -36.5 J
Using a free body diagram, the normal force is:
N = mg cos θ
N = (25 N) (4.90 m / d)
N = 122.5 J / d
Nd = 122.5 J
Therefore:
-(122.5 J) μ = -36.5 J
μ = 0.298
