Answer:
Objects between the source and observer produce possible shadows known as the umbra and the penumbra.
The umbra is a totally shadowed area, no light travels directly from the source to the observer.
The penumbra is a partially shadowed are where some of the source light travels directly to the observer an some of the source light is blocked from the observer (the object blocking the light is not a point object).
The question apparently refers to the differences seen by the observers.
Answer:
D
Explanation:
The rubber rod having been rubbed with fur get a net negative charge thereby gaining more mass which means the mass has increased compared to before it was rubbed against the fur while the glass rod having been rubbed with the silk to give it a net positive has lost mass and therefore has less mass compared to before it was rubbed on the silk.
Answer:
Explanation:
Given that,
Lightning flashes one mile (1609 m) away from you.
We need to find the time it take the light to travel that distance. Let the time be t. We know that,
speed = distance/time
So, the required time is 
Try to draw Humpty Dumty cracked on the floor with men all around him
