All 4 sides of a square are the same length.
If the perimeter of the square is 20-ft, then each side is 20-ft/4 = 5 ft.
If you increase the length of the square by 2-ft, then its new length is 5+2 = 7-ft.
If you decrease the width of the square by 1-ft, then its new width is 5-1 = 4-ft.
The area of the new figure is (length) x (width) = (7-ft x 4-ft) = <u>28 square feet</u>.
The kinetic energy of the roller coaster is 2000Joules
Given the formula for expressing the velocity of the roller coaster is given as:

Given the following parameter:
v = 10m/s
Substitute the given parameter into the formula to have:

Square both sides of the equation:

Hence the kinetic energy of the roller coaster is 2000Joules
Learn more on subject of formula here: brainly.com/question/657646
Find the average :8.4+7.5+12.9+10.6 divided by four
10/2.5= 4 the answer is 4 meters because you just divide them.