RI 2021 Y6 H2 Phy T3 CT QP B

© Raffles Institution [Turn over Name: ( ) CT Group: 21S0 RAFFLES INSTITUTION 2021 YEAR 6 JULY COMMON TEST H2 PHYSICS RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFLES INSTITUTION RAFFL ES INSTITUTION I Section B INSTRUCTIONS TO CANDIDATES Write your name, index number and CT Group. Write your answers to Section B in the spaces provided in this booklet. For Examiner’s Use Section A MCQ / 20 Section B 21 / 9 22 / 9 23 / 9 24 / 9 25 / 9 26 / 10 27 / 20 Deductions Total / 95 There are 21 printed pages, inclusive of the cover page, in this booklet.

2 © Raffles Institution Section B 21 (a) Hot air balloons used to be a means of transportation through the air. They are now commonly used for altitude sightseeing. The hot air balloon illustrated in Fig. 21.1 contains 800 m 3 of air at a constant temperature of 400 K. The density of the air at this temperature is 0.905 kg m−3. The air in the balloon was heated up from its initial temperature of 273 K at constant pressure and the specific heat capacity of the air under the conditions in which it wa s heated is 1050 J kg−1 K−1. (i) Calculate the mass m of air in the balloon at 400 K. m = kg [1] (ii) Determine the heat Q required to raise the temperature of the mass m of air from 273 K to 400 K. Q = J [1] (iii) The density of air is inversely proportional to its thermodynamic temperature at a constant pressure. Show that the density of air at 273 K is 1.33 kg m−3. [1] Fig. 21.1

3 © Raffles Institution [Turn over (iv) Hence, determine the volume which mass m of air occupies at 273 K. volume = m3 [1] (b) Fig. 21.2 shows that, during the heating process, air which was originally within the balloon spills out from the balloon. Calculate the work done on the atmosphere during this process. Atmospheric pressure is 1.03 × 105 Pa. work done = J [1] (c) Calculate the change in the internal energy of the mass m of air when heated from its initial temperature of 273 K to its final temperature of 400 K. change in the internal energy = J