Question

What should be the angular speed of earth, so that bodies lying on the equator may appear weightless ? (R = 6400 km, g = 10 m/s²)-

• A. 1.25 × 10^–3 rad/s
• B. 2.5 × 10^–3 rad/s
• C. 2.0 ×10^–3 rad/s
• D. 3.0 ×10^–3 rad/s

Answer 1

Answer: (A)

1.25 × 10^–3 rad/s

Answer 2

MRw² = Mg

w = $\sqrt{\frac{g}{R}}$= $\sqrt{\frac{10}{6400 \times 10^{3}}}$= 1.25 × 10^–3 rad /s

K = $\frac{\Delta P}{\frac{\Delta V}{V}}$= $\frac{2 \times 10^{6}}{\frac{0.1}{100}}$

= $\frac{2 \times 10^{8}}{0.1}$Nm^–2 = 2 × 10⁹ Nm^–2