A. 30cm
B. 25cm
C. 20cm
D. 15cm
E. 10cm

Correct Answer:

Option C – 20cm

Explanation

1/u + 1/3u = 1/15; u = 20cm

SEE ALSO  A force acts on a body for 0.5s changing its momentum from 16.0kg ms-1 to 21.0kgms-1, calculate the magnitude of the force.

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