Answer:
Part a)

Part b)



Part c)



Explanation:
Part a)
As we know that charge density is the ratio of total charge and total volume
So here the volume of the charge ball is given as



now the charge density of the ball is given as

Part b)
Now the charge enclosed by the surface is given as

at radius of 5 cm


at radius of 10 cm


at radius of 20 cm

Part c)
As we know that electric field is given as

so we have electric field at r = 5 cm


electric field at r = 10 cm


electric field at r = 20 cm


Answer:
Let No be initial no of atoms
N = N0 / 2 after 1 half-life
N = N0 / 4 after 2 half-lives
So after 2 half-lives 20 of the 80 atoms remain
Answer:
Complete this sentence. If the mass of object A is greater than object B, then the weight of object A will be heavier the weight of object B.
Explanation:
If the mass of Object A is more/greater than object B then it would be "heavier"
Ruff's image is 50m behind the mirror surface and the image is also 3m tall.
This is because it is a plane mirror.