To do this, we're going to use the order of operations (PEMDAS):
P - Parentheses
E - Exponents
M - Multiplication
D - Division
A - Addition
S - Subtraction
First let's do parentheses, there isn't anythig in parentheses we need to simplify, so we can skip this step.
Next let's look for exponents. I see we have a 
so let's replace that with 
:
Now let's look for multiplcation. We know that things that are right next to eachother in parentheses represent multiplcation, so let's simply this more:
And now we're left with a simple problem we know how to solve.
Answer: 
Hope this helps!
KE = 0 (because velocity is 0)
PE = mgh = 2kg*9.8m/s^2*40m= 784 joule
<u>Explanation:</u>
KE stands for kinetic energy. In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.
Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. Since in this case, the building is still and therefore it does not have any kind of kinetic energy because there is not acceleration.
A number is a perfect square (or a square number) if its square root is an integer; that is to say, it is the product of an integer with itself. Here, the square root of 20 is about 4.472. Thus, the square root of 20 is not an integer, and therefore 20 is not a square number.
18+5= n
n= 23
D. 23
15+5=20 so u just gotta add 5 to 18
