As the yeast feeds on sugar it creates carbon dioxide, and as the gas has no place to go it slowly fills the balloon up.
Answer: yes u can use a 6.75 when measuring the pencil
One horsepower is about 745.7 watts
For a simple harmonic motion energy is given with:

Where k is a constant that depends on the type of the wave you are looking at and A is amplitude.
Let's calculate the energy of the wave using two different amplitudes given in the problem:

We can see that energy associated with the wave is 4 times smaller when we decrease its amplitude by half. So the answer should be C.
C . plate a is negatively charged and plate b is positively charged