Answer:

Explanation:
using the law of the conservation of energy:


where K is the spring constant, x is the spring compression, N is the normal force of the block,
is the coefficiet of kinetic friction and d is the distance.
Also, by laws of newton, N is calculated by:
N = mg
N = 3.35 kg * 9.81 m/s
N = 32.8635
So, Replacing values on the first equation, we get:

solving for
:

Divide (25,000) by (the number of miles you can walk in 1 hour).
The answer you get is the number of hours it would take you to walk around the Earth once, IF you were able to walk on water too.
I’m pretty sure the answer would be D, sorry if it’s not correct!
Answer:
Q = - 256 X 10⁻⁷ C .
Explanation:
Electric field due to a charge Q at a distance d from the center is given by the expression
E = k Q /d² Where k is a constant and it is equal to 9 x 10⁹
Put the given value in the equation
9 x 10² = 
Q = 
Q = - 256 X 10⁻⁷ C .
It will be negative in nature as the field is directed towards the center.