Answer:
the second one i guess????
Explanation:
You need to know the speed and direction of object
Answer:
a) 
b) 
Explanation:
The frequency of the
harmonic of a vibrating string of length <em>L, </em>linear density
under a tension <em>T</em> is given by the formula:

a) So for the <em>fundamental mode</em> (n=1) we have, substituting our values:

b) The <em>frequency difference</em> between successive modes is the fundamental frequency, since:

Answer:
False -
F = G M1 M2 / R^2
So F depends on M1 and M2 and as long either is not zero there will be a gravitational force between them.
P = IV
I = P/V = 30 / 120 = 0.25 A.
Current = 0.25A