More practice questions

4. Q4. The mass of a body is measured with a 2% error and its speed with a 3% error. What is the percentage error in its kinetic energy, ½mv^²?

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   ΔK/K = Δm/m + 2Δv/v = 2% + 2 × 3% = 8%.

5. Q5. Z = A^²B/√C. The percentage errors in A, B and C are 1%, 2% and 4%. Find the percentage error in Z.

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   2 × 1% + 2% + ½ × 4% = 2% + 2% + 2% = 6%.

6. Q6. A length is measured as 20.0 cm with an absolute error of 0.5 cm. What is the percentage error?

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   0.5/20.0 × 100% = 2.5%.