Error in Measurement of Kinetic Energy Due to Positive Error in Velocity Measurement
Understanding the Relationship Between Velocity and Kinetic Energy:
The kinetic energy of a body is directly proportional to the square of its velocity. Mathematically, kinetic energy (KE) = 1/2 * mass * velocity^2. Therefore, any error in the measurement of velocity will directly impact the calculation of kinetic energy.

Calculating the Error in Kinetic Energy:
Given that there is a positive error of 50% in the measurement of velocity, the error in velocity measurement can be represented as 1 + 0.5 = 1.5 times the actual velocity. This means that the measured velocity is 150% of the actual velocity.
To calculate the error in kinetic energy, we square the error in velocity. Therefore, (1.5)^2 = 2.25. This implies that the error in kinetic energy will be 2.25 times the actual kinetic energy due to the error in velocity measurement.

Conclusion:
In conclusion, when there is a positive error of 50% in the measurement of velocity of a body, the error in the measurement of kinetic energy will be 125% (2.25 - 1 = 1.25, which is 125% expressed as a percentage) of the actual kinetic energy. It is crucial to consider and account for such errors in measurements to ensure accurate calculations and interpretations in scientific experiments and analyses.