Why Does the Force Meter Show Different Readings in Similar Situations?

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In summary, the varying readings of a force meter in similar situations can be attributed to several factors, including differences in measurement techniques, environmental influences, variations in the object being measured, and the calibration of the force meter itself. These elements can lead to discrepancies in the force measurements, highlighting the importance of consistent conditions and careful calibration for accurate results.
  • #1
Iamconfused123
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Homework Statement
I don't understand why is the soultion on 4th and last picture the way it is
Relevant Equations
F=ma
phy.png

I don't get how is the 4th case different from the 1st case? In both cases the weights are hanging and are not accelerating, but somehow in 4th case the force meter shows 0N while in 1st shows 10N.
All other meters show 10N but the last one.
Now, I don't know hot to solve last one. I tried treating it like pulley problem with two weights. Tried to calculate the acceleration, a=((M-m)/(M+m))*g, and then M(4kg)*a(6)=F=24N. But, it's not, apparently it's 16N.
Can someone please explain this to me? Thank you.
 
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  • #2
You are well on your way to solving the last problem. However, the force you have computed is the net force on the big mass. How is this related to the force on that mass due to the string tension?
 
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  • #3
Orodruin said:
You are well on your way to solving the last problem. However, the force you have computed is the net force on the big mass. How is this related to the force on that mass due to the string tension?
ohh, (a+g)×m(1kg)=16×1kg=16N. Or Tension on big mass= mg-ma=40N-24N=16N.

Thank you.
 
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  • #4
Orodruin said:
You are well on your way to solving the last problem. However, the force you have computed is the net force on the big mass. How is this related to the force on that mass due to the string tension?
Can you also help me with 4th example. Why in the 4th example the force meter shows 0N, If we have weight pulling on the spring on the right side, the weight on the left side is there just to keep the housing from moving, but that does not stop the weight on the right side to pull the spring, right?
 
  • #5
Iamconfused123 said:
Why in the 4th example the force meter shows 0N
It doesn’t. It shows 10 N.
 
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  • #6
Orodruin said:
It doesn’t. It shows 10 N.
Thanks, then solutions are wrong.
 
  • #7
Iamconfused123 said:
Tried to calculate the acceleration, a=((M-m)/(M+m))*g, and then M(4kg)*a(6)=F=24N. But, it's not, apparently it's 16N.
You have found the correct expression for the acceleration. $$a=\frac{M-m}{M+m}g=\frac{4-1}{4+1}\times 10~(\text{m/s}^2)=6~(\text{m/s}^2).$$ The net force on ##m## is up (positive) and is the sum of the unknown tension ##T## (up) plus the weight ##mg## (down).
##F_{\text{net}}=T +(-mg)=T-mg.##
Also, the net force on ##m## is equal to the mass times its acceleration according to Newton's second law. So
##F_{\text{net}}=T-mg = ma \implies T=m(g+a).##
Put in the numbers
##T=1~(\text{kg})\times(10+6)~(\text{m/s}^2)=16~\text{N}.##

The given answer is correct. In the last figure, no reading of the force meter is shown. Instead, we see a hint to use ##10~(\text{m/s}^2)## for the acceleration of gravity.
 

FAQ: Why Does the Force Meter Show Different Readings in Similar Situations?

Why does the force meter show different readings even when the applied force seems the same?

The force meter might show different readings due to calibration errors, variations in the surface on which the force is applied, or differences in the angle at which the force is applied. Environmental factors such as temperature and humidity can also affect the readings.

Can the type of force meter affect the readings in similar situations?

Yes, different types of force meters have varying sensitivities and accuracies. For instance, digital force meters might be more precise than analog ones, and some meters might be more susceptible to external factors like vibrations or electromagnetic interference.

How does the surface on which the force is applied influence the force meter readings?

The surface can greatly influence the readings. A rough or uneven surface can cause fluctuations in the force measurement, while a smooth and stable surface can provide more consistent readings. The material properties of the surface, such as friction and elasticity, also play a role.

Why do environmental factors like temperature and humidity affect force meter readings?

Temperature and humidity can cause materials within the force meter to expand or contract, leading to variations in readings. High humidity can also cause condensation, which might affect the electronic components of digital force meters, leading to inconsistent measurements.

What steps can be taken to ensure more consistent force meter readings?

To achieve more consistent readings, ensure that the force meter is properly calibrated before each use. Use the meter on a stable and uniform surface, and try to maintain a consistent angle of force application. Additionally, control environmental factors as much as possible by conducting measurements in a controlled environment.

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