Answer:
14 cm
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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Answer:
The moment of inertia is 
Explanation:
The moment of inertia is equal:

If r is 
and 


Answer:
D. The period would decrease by sqrt (2)
Explanation:
The period of a mass-spring system is given by:

where
m is the mass
k is the spring constant of the spring
If the spring constant is doubled,
k' = 2k
So the new period will be

So the correct answer is
D. The period would decrease by sqrt (2)