Question

A 1.83 kg book is placed on a flat desk. Suppose the coefficient of static friction between the book and the desk is 0.442 and the coefficient of kinetic friction is 0.240 . How much force is needed to begin moving the book?

Answer 1

Answer:7.92 N

Step-by-step explanation:

Given

mass of book
`m=1.83\ kg`

coefficient of static friction
`\mu _s=0.442`

coefficient of kinetic friction
`\mu _k=0.240`

To move the book, one need to overcome the static friction

Static friction
`F_s=\mu _sN`

`F_s=\mu _s* 1.83* 9.8`

`F_s=0.442* 1.83* 9.8`

`F_s=7.92\ N`

After overcoming the Static friction , Force needed to move the block is

`F_k=\mu _kN`

`F_k=0.240* 1.83* 9.8`

`F_k=4.30\ N`