6. An igloo, a hemispherical enclosure built of ice (1.67 J/m-sC), has as inner radius of 2.50m. The thickness of the ice is 0.5m. At what rate must thermal energy be generated to maintain the air inside the igloo at 5C when the outside temperature is -40C? Ignore all thermal energy losses through the ground or by air currents. S 0.5m ice sha (a) 2.25 kW 7. 8. (b) 4.5 kW 2.5m (c) 1.25 kW (d) 5 kW Assume temperature of 27C, p = 105 Pa, n = 1 mole diameter of air molecules as 1010m, which of the following is correct? (a) Mean free path > interatomic spacing (c) Mean free path < interatomic spacing (b) Mean free path = interatomic spacing (d) Data insufficient A car is moving towards a stationary observer at a speed of 108 km/hr. The speed of sound is 330 m/s. If the observer hears the frequency of horn as 550 Hz, what frequency will he hear after the car has passed? (a) 550 Hz 9. (b) 500 Hz (c) 458.33 Hz (d) 421.6Hz Two blocks of same mass but different density p, & p are floating in water. Block-2 has higher fraction of its volume submerged in water. If buoyant force on them are B & B :- 1 (a) B > B2, P>P (b) B