Problem 5 A window washer pushes his scrub brush up a vertical window at constan

Question

Problem 5 A window washer pushes his scrub brush up a vertical window at constant speed as shown in the figure (Figure 1). The head of the brush (when wet) weighs 14.3N and the coefficient of kinetic friction between the bristles and the window surface is 0.190. Part A Calculate the magnitude of the force F exerted on the head of the brush by the handle of the brush: the direction of the force F is as shown in the figure. F= N Part B Submit Calculate the magnitude of the normal force exerted on the brush by the window. N= N

Explanation / Answer

F* cos(53.1) = N

F* sin(53.1) = 0.19*N + 14.3

therefore, 0.6F = N

and 0.8F = 0.19N + 14.3

Substituting equation 1 in 2,

we get 0.8F = 0.19*0.6F + 14.3

F = 20.845

N = 12.5

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.