Double
Explanation:
Since the period T of a pendulum is given by

By increasing the length of the pendulum by 4, the period becomes

You can see that the period doubles when we increase the length by a factor of 4.
Answer: [B]: The letter, "<em /> I " ; for current; in units of "Amps" .
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D. March because it is just below the 1 million marker on the graph and it is the only one that low.
A.is an example of decomposition reaction.
The volume of the balloon will halve
Explanation:
Boyle's law states that for an ideal gas kept at constant temperature, the pressure of the gas is proportional to its volume. Mathematically,

where
p is the gas pressure
V is the volume
The equation can also be rewritten as

And if we apply it to the gas inside the balloon in this problem (assuming its temperature is constant), we have:
is the initial pressure at sea level (the atmospheric pressure)
is the initial volume
is the final pressure
is the final volume
Substituting into the equation, we find:

Which means that the volume of the balloon will halve.
Learn more about ideal gases:
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