Question

The earth moves round the sun in a near circular orbit of radius $1.8 \times 10^{11}\, m$. Its centripetal acceleration is:

• A. $6 \times 10^{3}\, m/s^{2}$
• B. $10 \times 10^{3}\, m/s^{2}$
• C. $12 \times 10^{3}\, m/s^{2}$
• D. $10^{-3}\, m/s^{2}$

Answer 1

Answer: (A)

Centripetal acceleration, $a_{c}=\omega^{2} R$
$=\frac{(2 \pi)^{2} \times R }{ T ^{2}}=\frac{4 \times(3.14)^{2} \times 1.8 \times 10^{11}}{(365 \times 24 \times 60 \times 60)^{2}}$
$=\frac{4 \times 10 \times 1.8 \times 10^{11}}{\left(31536 \times 10^{3}\right)^{2}}$
$=6 \times 10^{-3} m / s ^{2}$