We are missing an important piece of information needed to answer this question: the number of kcal Charles losses per day. However, we can come up with a general equation in which kcal/day is the only independent variable.
We know that it takes 3500 kcal to lose one pound. To lose 5 pounds, Charles needs to lose 5 x 3500 kcal = 17,500 kcal.
To find how many days it takes Charles to lose 17,500 kcal (5 pounds), we must divide that amount by the number of kcal Charles loses per day.
Here is the equation to calculate that number
Number of days= 17500 / (kcal per day)
If given calories, remember that 1000 calories = 1 kcal, and .001 kcal = 1 cal
Explanation:
Given that,
Force with which a child hits a ball is 350 N
Time of contact is 0.12 s
We need to find the impulse received by the ball. The impulse delivered is given by :

So, the impulse is 42 N-m..
We know that he change in momentum is also equal to the impulse delivered.
So, impulse = 42 N-m and change in momentum =42 N-m.
C. Elements
elements are found in periodic table (in 1 box)
Missing figure of the problem: http://tsephysics.weebly.com/uploads/5/1/9/3/51934203/477140_orig.jpg
Solution:
Assuming the potential is zero at infinite distance from the charge, then the potential at a certain distance r from a single point charge is

where

is the Coulomb's constant.
In our problem, we just have to superimpose the potential generated by every charge. The diagonal of the square is

, therefore the distance between each charge and the center of the square is

.
So, the total potential is:

