Forces and work on an incline help

AI Thread Summary
The discussion revolves around a lab experiment measuring the force on a concrete block (15.8 kg) on an inclined wooden ramp. As the ramp angle increases, the force required to pull the block also increases, which aligns with expectations. The coefficient of friction is being analyzed at various angles, revealing values greater than 1 at around 47 degrees, which raises questions about the calculations. Participants are considering the normal force as a cosine function of weight and the parallel force as the applied force up the ramp, but there is uncertainty about the accuracy of this approach. Clarification is sought on how to incorporate the components of weight down the incline into the equation for calculating the coefficient of friction.
northern expo
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we are conducting a lab where measurement of force on an incline is necessary. the mass which is pulled is a small concrete block (15.8 kg) on a wooden ramp. as the ramp is increased the force changes (increasing) which is expected. last we need to look at the coefficient of friction at different angles of measure. if we are pulling the block up the ramp at a constant we are finding a force of oppositon due to friction and the force normal. ok, as we are calculating we are finding that the value of this coefficient is increasing and at about 47 degrees of the horizontal plane this value is greater than 1! at the lower angles it is a reasonable value. what are we forgetting? yes we are considering that the force normal is a cosine function of the weight and the force parrallel is the froce we are applying up the ramp. doesn't seem to be correct. what are we missing?
 
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northern expo said:
we are conducting a lab where measurement of force on an incline is necessary. the mass which is pulled is a small concrete block (15.8 kg) on a wooden ramp. as the ramp is increased the force changes (increasing) which is expected. last we need to look at the coefficient of friction at different angles of measure. if we are pulling the block up the ramp at a constant we are finding a force of oppositon due to friction and the force normal. ok, as we are calculating we are finding that the value of this coefficient is increasing and at about 47 degrees of the horizontal plane this value is greater than 1! at the lower angles it is a reasonable value. what are we forgetting? yes we are considering that the force normal is a cosine function of the weight and the force parrallel is the froce we are applying up the ramp. doesn't seem to be correct. what are we missing?

F = m*g*sinθ + μ*m*g*cosθ

I'm just saying, since you didn't mention the component of weight down the incline at sinθ.
 
is this F value you are indicating the net F ? We have a measured value for the force up the incline, how is this value

F = m*g*sinθ + μ*m*g*cosθ

included into my equation to find the coefficient value?
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...

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