Answer:
In order to make a sound wave have a higher pitch you increase the frequency.
In order to increase the volume of a sound wave, you have to increase the amplitude.
Hope this helps!
Larger mass creates a stronger pull
Answer:
the mass of the body is 0.02 kg.
Explanation:
Given;
relative density of the oil,
= 0.875
mass of the object in oil,
= 0.013 kg
mass of the object in water,
= 0.012 kg
let the mass of the object in air = 
weight of the oil, 
weight of the water, 
The relative density of the oil is given as;

Therefore, the mass of the body is 0.02 kg.
Answer: They will repel each other.
Explanation:
Two inflated balloons when rubbed with woolen cloth will lead to repeal each other because of the similar charges on both the balloons.
Rubbing both the balloons together by the woolen cloth will introduce negative charge in the balloons.
As, we know that the same charges repeal each other both of the balloons with be apart from each other.
This is due to the static electricity, the negatively charged particles jump to the positive one. When balloons are rubbed they become negatively charged.