# Mock exam paper C Ordinary Level

 PRE-LEAVING CERTIFICATE EXAMINATION, 2013____________Physics - Ordinary level____________3 Hour DurationAnswer three questions from Section A and five questions from Section B

N.B. Relevant data are listed in the Formulae and Tables booklet

SECTION A (120 marks)

Answer three questions from this section.

Each question carries 40 marks.

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1. In an experiment to verify the principle of conservation of momentum the student reported the following:

I set up the necessary apparatus. I measured the masses of the two trolleys . I measured the distance travelled and the time to travel this distance and hence calculated the velocities of the trolleys. Using that data I verified the law of conservation of momentum

(i) draw a labelled diagram of the apparatus used (12)

(ii) describe how the student measured time in the experiment (6)

(iii) How did the student calculate the velocity of the trolleys (9)

(iv)How did the student calculate the momentum of the trolleys? (6)

(v) how did the student verify the law of conservation of momentum? (7)

1. The student performed an experiment to measure the focal length of a concave mirror. The following table of results were obtained
 Object distance from mirror (u) /cm Image distance from mirror (v) /cm 29 64 37 43 40 41 50 35 55 33 60 30

Describe how the image position was located (9)

Plot a suitable graph and, from the graph, calculate an average value for the focal length of the mirror (24)

Give two sources of error in measuring the image distance and state how one of these errors can be reduced (7)

1. In an experiment to measure the specific latent heat of vaporisation a student added steam at 100oC to water in a calorimeter and noted the change in temperature

Draw a labelled diagram of the apparatus used in the experiment (9)

List all the measurements which must be taken by the student (15)

The student used a steam trap to ensur...