friction pulley. One end of the rope is connected to box2 and the other is connected to box3. The weights of the three boxes are W1=55N, W2=35N, W3=28N. Determine the magnitude of the normal force that the table exerts on box 1..............The answer is 62 N, i just have no idea how to get to that...please help
2006-11-10 16:36:39 · 5 answers · asked by Vanessa M 1 in Science & Mathematics ➔ Physics
is the ques complete is there any friction between the boxes or any other force. can't understand the ques itself do we have a figure somewhere
2006-11-10 16:48:31 · answer #1 · answered by yog 2 · 0⤊ 0⤋
Let's draw:
--------Pulley
[W3] 1
v ^W3
1
1
1 Total weight = W1&W2=90N
[W2]
[W1]
^
1 Force exerted by table
1
It's not a good diagram, and maybe worse when sent to you because of distortion. What I'm trying to point
out is that the weight W3 is balanced by the rope passing through the pulley.
The rope tied to W2 and W3 will have a tension equal to W3 and opposite in direction to the weights of W1 and W2. There are 3 vertical forces: W1 and W2, both downward, and the tension equal to W3 upward. The table will exert a force on box 1 equal to W1+W2-W3. Substitute the given values and you will get a force of 62N.
A more detailed explanation:
Your upward forces are the tension on the rope equal to W3 and the force exerted by the table on box 1. Let's call it P. The downward forces are W1 and W2. All the forces are in equilibrium. Therefore
P+W3=W1+W2.
P=90-28
=62N
This type of problem will be simpler if it is accompanied by a diagram. Otherwise, the student will just have to use his imagination --as I did--as to how to arrive at the answer of 62N.
2006-11-11 00:47:41 · answer #2 · answered by tul b 3 · 0⤊ 1⤋
On one side of the pulley you have an aggregate mass of 90N. Going through a pulley and on the other end you have a mass of 28N.
Imagine your fat bother ans sister (mass of 55N & 35N) sitting on one side of a seesaw and you on the other at a meager 28N (you haven't bee fed for a while.
If you add thier total mass you get 90N. You are now countering thier mass on the other end of the seesaw (or pulley) at 28N.
Simply take your mass away for thier total mass and you have your answer.
55N + 35N = 90N
90N - 28N = 62
2006-11-10 16:49:03 · answer #3 · answered by Triestobewise 3 · 0⤊ 0⤋
You need to re-phrase the question. Things are missing.
2006-11-10 20:25:51 · answer #4 · answered by kapilbansalagra 4 · 0⤊ 0⤋
2???
POINTS that is, thx.
2006-11-10 16:42:09 · answer #5 · answered by Mr Rogers best friend 2 · 0⤊ 0⤋