A 50 kg man on centre of a 30 kg, 10 m long platform pulls a rope attached to a 50 kg box. Platform–ground μ = 0.2, box–ground μ = 0.5, shoes–platform μ = 0.6. Box moves slowly while man remains fixed relative ground. Time until the platform slides out from under man is √(10/k) s; find k (g = 10 m s⁻²). [See Image.]
Physics · Mixed Chapter
A 50 kg man on centre of a 30 kg, 10 m long platform pulls a rope attached to a 50 kg box. Platform–ground μ = 0.2, box–ground μ = 0.5, shoes–platform μ = 0.6. Box moves slowly while man remains fixed relative ground. Time until the platform slides out from under man is √(10/k) s; find k (g = 10 m s⁻²). [See Image.]