A 160-kg box is at rest on a warehouse floor. A worker pulls on a rope attached

Question

A 160-kg box is at rest on a warehouse floor. A worker pulls on a rope attached to the box with a force of 986 N directed at an angle of 32 degrees above the horizontal. Despite the workers best efforts, the box does not start to move. What is the magnitude of the frictional force f acting from the floor on the box? bullet When solving force problems, always draw a proper free-body diagram. bullet Explain the diagram. bullet Find representations for the components of all force vectors. bullet Set up Newton's Law for the separately for the x and y directions. bullet Find the missing quantities. bullet Evaluate your answer: For this problem you could try limiting cases; for example, can you predict what the answer is for the two limiting cases of the angle approaching 0 degree and 90 degree. Does your answer follow that prediction?

Explanation / Answer

As the box is not moving net force acting on it must be zero.

Fnety = 0

T*sin(32) + N - W = 0

N = W - T*sin(32)

= 160*9.8 - 986*sin(32)

= 1045.5 N

now Apply, Fnetx = 0

T*cos(32) - f = 0

==> f = T*cos(32)

= 986*cos(32)

= 836.2 N <<<<<<<<<<<<----------------Answer

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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