Question 6:
Write down the symbol ‘+’ for increase, the symbol ‘–’
for decrease and the symbol ‘0’ for no change,
0
;
+
+
+
0
+
+
0
i)
ii)
iii)
CIE
A2-LEVEL
PHYSICS//9702
P
AGE
9
OF
37
Question 2: Some water in a saucepan is boiling. a)Explain why: i.external work is done by the boiling water
∆= ² g
z
+ g
{
b)
By reference to the first law and your answer in (a),
show that thermal energy must be supplied to the
water during the boiling process
∆= ² x + y
Changing from a liquid to a gas, there is an increase
in internal energy. Work is done by the liquid so
y
is
negative. For
∆=
to be positive,
x
must increase.
6.
O
SCILLATIONS
6.1 Describing Oscillations
Displacement
#|$
:
instantaneous distance of the moving
object from its mean position
Amplitude
#}$
:
maximum displacement from the mean
position
Period
#~$
:
time taken for one complete oscillation
Frequency
# $
:
number of oscillations per unit time
Angular frequency
# $
:
rate of change of angular
displacement
µ ² 2·¹
Phase difference # $:measure of how much one wave is out of step with another wave
