Question

. The lengths of two bodies measured by a meter scale are l1 = (20 ± 0.5) cm and l2= (15 ± 0.2) cm. Calculate sum of these lengths.

Answer 1

Answer:

• L₁ = 20 cm
• L₂ = 15 cm
• ∆L₁ = 0.5 cm
• ∆L₂ = 0.2 cm

$\implies L = L_1 + L_2 \\ \implies L = 20+ 15 \\ \implies \bf{L = 35 \: cm}$

$\implies \Delta L = \Delta L_1 +\Delta L_2 \\ \implies \Delta L = 0.5 + 0.2$

$\implies \Delta L = \Delta L_1 +\Delta L_2 \\ \implies \bf \Delta L = 0.7 \: cm$

Therefore, final answer:

$\implies \red{ (35 \pm0.7) \: cm}$