Question

A block with mass m1 = 8.8 kg is on an incline with an angle θ = 41.0° with respect to the horizontal. For the first question there is no friction, but for the rest of this problem the coefficients of friction are: μk = 0.39 and μs = 0.429.



Now a new block with mass m2 = 16.4 kg is attached to the first block. The new block is made of a different material and has a greater coefficient of static friction. What minimum value for the coefficient of static friction is needed between the new block and the plane to keep the system from accelerating?

Answer 1

kx = mgsin(theta)
k = mgsin(theta)/x
=8.8*9.8*sin(41)/(.13)

Answer 2

how come it keeps telling me that its incorrect?

Answer 3

what did you get

Answer 4

435.22

Answer 5

probably supposed to be using friction for this one.

Answer 6

yea i think we are

Answer 7

"For the first question there is no friction, "

bit misleading eh?

Answer 8

o man im sorry! thats not the first question its the last 2.. i just posted the questions i couldnt answer

Answer 9

im sorry!

Answer 10

heh

so: kx = mgsin(theta) -us*mg*cos(theta)

... I guess. It actually depends on whether you hook on the spring and then let the block slide to a stop or whether you hold the block in place at the distance you calculated and then hook the spring on...

Answer 11

what is the us?

Answer 12

oo nvm im dumb its the static

Answer 13

yess thank u got it!

Answer 14

cool

Answer 15

what about the second part?

Answer 16

don't know; what is the second part?

Answer 17

Now a new block with mass m2 = 16.4 kg is attached to the first block. The new block is made of a different material and has a greater coefficient of static friction. What minimum value for the coefficient of static friction is needed between the new block and the plane to keep the system from accelerating?

Answer 18

sum them all up, result is zero :)

Answer 19

it says zero is inccorect?

Answer 20

sum up the forces... they equal zero. solve for mu s of the second block.

Answer 21

oo ok gotcha thank you

Answer 22

the solution is:

Answer 23

good luck

Answer 24

did you actually get a coefficient of friction >1 ??

wow.

Answer 25

why put the observation must be some error in the data, there are some cases of coefficients greater than one but are strangers.

Answer 26

Sticky things can have a coefficient of friction greater than 1.

Answer 27

so which is the actual answer?

Answer 28

we are working on dry

Answer 29

ok thnx

Answer 30

Following the approach is the answer, unfortunately values ​​are not appropriate.
good luck