Answer:
This process is known as static electricity
Explanation:
When balloon is rubbed on the wool , a negative charge is usually formed. When the balloon is then held over—but not touching—some bits of paper, some of the bits jump up to the balloon. The bits which jump up to the balloon are positive charged and we know that unlike charges attract.
This process explains static electricity which is when the charges on a material are not in a balanced state.
Answer:
B) 3.50 m/s
Explanation:
The linear velocity in a circular motion is defined as:

The angular frequency (
) is defined as 2π times the frequency and r is the radius, that is, the distance from the center of the circular motion.

Replacing (2) in (1):

We have to convert the frequency to Hz:

Finally, we calculate how fast is the child moving:

Answer:
Sodium is stored under paraffin oil
Explanation:
Group 1 metals are known to be very highly reactive. The chemical reactivity of the members of the group decreases down the group.
Sodium reacts violently with water and upon exposure to the atmosphere. As a result of this, it must be stored under paraffin oil.