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Chapter 7: Q. 19 (page 178)

A woman living in a third-story apartment is moving out. Rather than carrying everything down the stairs, she decides to pack her belongings into crates, attach a frictionless pulley to her balcony railing, and lower the crates by rope. How hard must she pull on the horizontal end of the rope to lower a 25kgcrate at steady speed?

Short Answer

Expert verified

The horizontal force is242.25N

Step by step solution

01

Given information

Mass of the crate attached to a frictionless pulley, m=25kg

The crater is moving at a steady speed.

02

Explanation

The horizontal force on the rope will balance the weight of the crate and will not allow it to fall with acceleration , so it will fall with uniform velocity if horizontal force becomes equal to weight of crate.

F=mgm=25kgg=9.81m/s2F=25kg9.81m/s2=245.25N

The horizontal force is 245.25N

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