Question

Two large books are stacked on top of each other on a table . The mass of each book is 6.5Kg Given that the coefficient of static friction between bottom book and table is 0.15, what is the lowest the coefficient of static friction between the books can be in order to apply force and move both books?

Answer 1

Answer in textbook is 0.30

Answer 2

so you want to know how to do this right?

Answer 3

yes but please consider that this is a gr.11 physics problem

Answer 4

ok

Answer 5

multiply the force of the object perpendicular to the surfis by the coefficient of friction
is the frictional force
and i'm in 7th grade i think i can cope maby

Answer 6

Yes I can conclude that a long time ago, but I want the process and why is that the process. Thanks for trying though

Answer 7

now can i have a medal
please

Answer 8

ok sorry i had some lagg and did not see your messege

Answer 9

np

Answer 10

because the bumps of the object determen the coefficient of friction...

Answer 11

i have to go in a min

Answer 12

could you demonstrate what you said mathematically please ? thanks

Answer 13

do u want me to explain it to you or have you figured it out?

Answer 14

yes please explain it to me

Answer 15

its difficult to type it. ill just solve it and post a picture of it.

Answer 16

sure np

Answer 17

is the answer 0.3?

Answer 18

yes, the textbook says that

Answer 19

alright. so for minimum coefficient, we need to make an assumption that its going to be going at a constant velocity

Answer 20

in other words, the force applied will be equal to Fmax

Answer 21

and acceleration 0

Answer 22

now, for the upper book to move together, it should have the same constant velocity

Answer 23

which means that the friction on upper book equals friction on lower book

Answer 24

which if you solve will give the coefficient

Answer 25

so, 0.15*13g=u*6.5g. will give u=0.3

Answer 26

ahaa ok ! I see now where I was wrong before in my trials. Thanks a lot :D

Answer 27

hey are you there?

Answer 28

is the force given?

Answer 29

no

Answer 30

so in the fed of the top book what horizontal forces do u think will be present?

Answer 31

only friction right?

Answer 32

if there was only friction, wouldn't the upper block accelerate?

Answer 33

No, I am assuming that some sort of force acted on it horizontally. At the end, I figured out the answer in a different approach than yours. Thanks anyways :)

Answer 34

what did u do?

Answer 35

or rather, how did you do it?

Answer 36

I will answer you later :) , I have a test tomorrow that I am studying for tomorrow.

Answer 37

oh sorry for disturbing