The value of acceleration due to gravity g on the surface of Earth depends on MCQ with Answer and Explanation

Explanation:
First, convert speed to SI units: 72 km/h = 72 × (5/18) m/s = 20 m/s. Initial velocity (u) = 0, final velocity (v) = 20 m/s, time (t) = 10 s. Acceleration (a) = (v-u)/t = 20/10 = 2 m/s². Distance (s) = ut + (1/2)at² = 0 + 0.5 × 2 × 10² = 100 meters.

Explanation:
Geostationary satellites orbit in Earth's equatorial plane with period matching Earth's rotation period (24 hours), so they appear stationary relative to ground. Orbital radius is about 42,000 km from Earth's center. Memory tip: 'Geostationary: T=24 h, equatorial orbit, fixed position; used for communication/weather satellites'. This standard result is frequently tested in competitive exams. Always recall that geostationary is a special case of geosynchronous (same period) with zero inclination; competitive exams often compare low orbit (84 min) vs geostationary (24 h) periods.

Explanation:
Fraction of volume submerged = ρ_ice / ρ_water. If 1/10 above, 9/10 submerged. So ρ_ice/ρ_water = 9/10 => ρ_ice = 0.9 g/cm³. Density of ice is 0.9 g/cm³.