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# 1 Physics Q.

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## Replies to: 1 Physics Q.

• Registered User Posts: 513 Member
Well you said the large block and the floor are frictionless so they must be accelerating since there is no opposing frictional force between the block and floor.
• Registered User Posts: 4,706 Senior Member
Ok. I redid the problem with acceleration now.

Now I get F = (mg + mu_s *ma)/mu_s. How do I get the acceleration a?
• Registered User Posts: 4,706 Senior Member
I think I got it. To get the acceleration a, I looked at the entire system consisting of both masses.

F = (m + M)a
a = F/(m+M)

I plugged a back into F = (mg + mu_s *ma)/mu_s and solved for F. Now I get 487.65 N, which is much closer to the correct answer of 490 N.
• Registered User Posts: 513 Member
That looks good. The discrepancy is probably due to sig figs
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