What is the total force exerted by block 2 on block 3 ?

  • Thread starter Thread starter aruji73
  • Start date Start date
  • Tags Tags
    Block Force
AI Thread Summary
The discussion centers on calculating the total force exerted by block 2 on block 3 in a system of four blocks on a frictionless table. Initially, a participant calculated the force as 67.5 N, which was incorrect. They later considered the combined weight of the two blocks above block 2, calculating it as 196 N, but still faced issues with the horizontal force component. The conversation emphasizes the importance of analyzing both horizontal and vertical forces to determine the net force accurately. Ultimately, the correct approach involves understanding the vector nature of the forces acting on the blocks.
aruji73
Messages
19
Reaction score
0
Four blocks EACH of mass m = 10.0 kg are arranged as shown in the picture, on top of a frictionless table. A hand touching block 1 applies a force of Fh1 = 90.0 N to the right. The coefficient of friction between the blocks is sufficient to keep the blocks from moving with respect to each other.

What is the total force exerted by block 2 on block 3 ?

I got 67.5 N which was wrong

F=90N-22.5=67.5N since a=9/4ms-2
 

Attachments

  • blocks.gif
    blocks.gif
    2.4 KB · Views: 741
Physics news on Phys.org
Start by drawing a free-body diagram showing all the forces. Pay particular attention to blocks 2 and 3, but don't ignore the others.
 
I now think block 2 would exert a force to block 3 equal to the combined weight of the 2 books above it which is f=2(mg) = 2*10*9.8 = 196 N

but i still get it wrong
 
That's part of it, but what about the horizontal direction?
 
i got it now its sqrt(of horizontal direction ^2 + vertical direction ^2)
 
Assuming you are referring to the forces on the block, that is indeed the magnitude of the net force. Now what is the direction?
 
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Trying to understand the logic behind adding vectors with an angle between them'
My initial calculation was to subtract V1 from V2 to show that from the perspective of the second aircraft the first one is -300km/h. So i checked with ChatGPT and it said I cant just subtract them because I have an angle between them. So I dont understand the reasoning of it. Like why should a velocity be dependent on an angle? I was thinking about how it would look like if the planes where parallel to each other, and then how it look like if one is turning away and I dont see it. Since...
Back
Top