Questions on Energy Transitions

Q10.

(a) Each of the four objects shown above started at room temperature. Now they are all at different temperatures, as described by the labels.

(i) Which object is at the highest temperature?

The tiny white hot spark.

1 mark

(ii) Which object has lost thermal energy?

The glass of water

1 mark

(iii) Which object has had the largest gain in thermal energy?

The red hot poker

1 mark

(b) Omar puts a hot steel ball into a beaker of cold water. He waits until the temperatures of the ball and the water are the same. From his results, he calculates that:

the thermal energy stored in the steel ball has fallen by 3770 J
the thermal energy stored in the water has risen by 2940 J
The energy stored in the water rose by less than 3770 J

What has happened to the other 830 J?

The energy has been transferred to the beaker (or air) or dissipated in the surroundings

Accept 'the energy has been lost during evaporation' or 'used to form steam'

1 mark

Maximum 4 marks