Problem concerned to kinematics

[Mareena]

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

 

[tiny-tim]

Hi Mareena!

(please don't use txt speak on this forum )

… 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