Answer:
14 cm
Step-by-step explanation:
F = (frac{uv}{u – v})
F = +ve
v = -ve
30 = (frac {25 {times} (-v)}{25 – (-v)})
v = (frac {25 {times} (-v)}{25+v})
v = 14cm
(Note that either negative or positive values go to show the positioning and hence, they are not a strong necessity in your final answer.)
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