Page 72 - SP015 Past Years PSPM Chapter 6 -14 Ver 2020

PHYSICS PSPM SEM 1 1999 - 2017

PSPM JAN 1999/2000 SF015/2 No. 14(b)

-2
11. p (N m )
K L
5

1
J M
3
V (m )

FIGURE 14.2

FIGURE 14.2 shows the graph of pressure p versus volume V of an ideal gas system.
The change in internal energy for the gas from K to M is +400 J, while the work done
along the path of KLM is +100 J.

(a) How much thermal energy must be added to the system during the K to L to M
process? [2 m]

(b) Determine the work done by the system for the process from M to J. [3 m]

(c) Calculate the thermal energy with the environment during M to K process. [2 m]

PSPM JUN 1999/2000 SF015/2 No. 14(c)

12. pressure

2p o A

p o C
B
V o volume
0.5V o
FIGURE 14.3

A 0.5 mole of ideal gas change from A to C as shown in FIGURE 14.3.
-2
-2
5
3
If V o = 3.0  10 m and p o = 1.5  10 N m , determine

(a) the total change of internal energy in the gas. [5 m]

(b) the total heat supplied to the gas. [3 m]

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