Problem concerned to kinematics

  • Thread starter Thread starter Mareena
  • Start date Start date
  • Tags Tags
    Kinematics
AI Thread Summary
The discussion centers on calculating the maximum error in kinetic energy estimation due to percentage errors in mass and speed measurements, which are 2% and 3%, respectively, resulting in an 8% maximum error. The formula for kinetic energy, K = mv^2/2, is referenced, and the relationship between changes in kinetic energy and the errors in mass and speed is expressed as dK/K = dm/m + 2dv/v. A participant seeks clarification on the derivation of this equation. It is explained that the equation is derived from differentiating the logarithmic form of the kinetic energy equation. Understanding this derivation is crucial for accurately assessing measurement errors in physics.
Mareena
Messages
6
Reaction score
0
The percentage errors in the measurement of mass and speed are 2 % and 3% respectively.how much wil be the maximum error in the estimate of kinetic energy obtained by measuring mass and speed?
its ans is 8 % ..
according to this equation K = mv^2/ 2 , so dK / K = dm/m + 2dv / v
( d means delta ) .. but the problem is , where dat second equation has been derived from? please help
 
Physics news on Phys.org
Hi Mareena! :smile:

(please don't use txt speak on this forum :redface:)
Mareena said:
… K = mv^2/ 2 , so dK / K = dm/m + 2dv / v
( d means delta ) .. but the problem is , where dat second equation has been derived from?

it comes from differentiating logK = logm + 2logv + logconstant :wink:
 
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...
Back
Top