Answer:5250 N
Explanation: ig:iihoop.vince
To find average speed, we divide the distance of travel (in this case, 400 metres) by the time she took, 32 seconds. Therefore: 12.5 seconds is her average speed.
No. A mirror works because of reflection.
Answer:

Explanation:
The volume charge density is defined by ρ =
(Equation A), where Q is the charge and V, the volume.
The units in the S.I. are
, so we have to express the radius in meters:
inner radius = 
outer radius = 
Now, we know that the volume of the sphere is calculated by the formula:
, and as we have an spherical shell, the volume is calculated by the difference between the outher and inner spheres:
V =
, where
is the outer radius and
is the inner radius.
Replacing the volume formula in the Equation A:
ρ = 
ρ = 
Replacing the values of the outer and inner radius whe have:
ρ = 
ρ = 