While falling, both the sheet of paper and the paper ball experience air resistance. But the surface area of the sheet is much more than that of the spherical ball. And air resistance varies directly with surface area. Hence the sheet experiences more air resistance than the ball and it falls more slowly than the paper ball.
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Answer:

Explanation:
As we know that the position of maximum intensity on the screen is given as

here we know that
= wavelength
L = distance of the screen
d = distance between two slits
now we know that the position of 8th maximum intensity is same as that of 9th maximum on the screen
so we have

so here we have


Its option 3 an object has potential energy
Answer:
polystyrene is a good insulater so less heat will escape from the cup and it will keep it warm.
the cup helps it become more insulated