Question

A mass M is initially at rest on a horizontal surface, μs=0.30 and μk=0.20 . A horizontal string then pulls M with a tension T. Forces below are magnitudes. Indicate if each statement is correct or incorrect

If M does not accelerate, then T ≤ μsN
M will accelerate if T exceed μsN
The NET force on M (if M does not move) is T
N equals Mg
T equals μsN if M remains at rest
M will accelerate if T exceeds μkN

Answer 1

Hey, you try first.

Answer 2

I have already and the answers I submit is wrong.



If M does not accelerate, then T ≤ μsN I
M will accelerate if T exceed μsN I
The NET force on M (if M does not move) is T C
N equals Mg C
T equals μsN if M remains at rest C
M will accelerate if T exceeds μkN I

Answer 3

If M does not accelerate, then T ≤ μsN I

If it is already moving then it may accelerate with T < musN so I agree false
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M will accelerate if T exceed μsN I

Yes it will because it will start and then the force is greater than needed for a constant speed. I say True
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The NET force on M (if M does not move) is T C

NO, if it does not accelerate the NET force is zero. (the friction exactly balances T) False
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N equals Mg C

Yes, correct
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T equals μsN if M remains at rest C

False, T = mus N only at the point where it starts to move. For smaller T, mus N is greater than T
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M will accelerate if T exceeds μkN I

True if and only if the mass is already moving.

Answer 4

Those answers are coming up as wrong too. This problem is really frustrating me. I don't know what else to do.

Answer 5

I got this exact homework but my questions are slightly different. Maybe it can help u or some one else.

N equals Mg [Correct]
If M does not accelerate, then T ≤ μsN [Correct]
M will accelerate if T exceed μsN [Correct]
The NET force on M (if M does not move) is μkN [Incorrect]
M will accelerate if T exceeds μkN [Incorrect]
T equals μsN if M remains at rest [Incorrect]