Question

Kickboxing it's found the force needed to break a board varies inversely with the length of the board it takes 9 pounds of pressure to break a board that is 3 feet long how long is the board that requires 5 pounds of pressure to break

Answer 1

Answer:

If f=5 pounds of pressure, l=5.4 feet long

Step-by-step explanation:

Force needed to break a board varies inversely with the length of the board

Let

Force to break the board=f

Length of the board=l

f=k/l

Where k is a constant

If f=9 pounds of pressure and l=3 feet long

f=k/l

9=k/3

Cross product

9*3=k

27=k

If k=27, f=5 pounds of pressure. Find l?

f=k/l

5=27/l

Cross product

5l=27

l=27/5

=5.4

l=5.4 feet long

Answer 2

Using proportions, it is found that the board that requires 5 pounds of pressure to break is 1.67 inches long.

Proportions:

• This question is solved by proportions, using a rule of three.

• It takes 9 pounds to break a board that is 3 feet long, what is the length of a board that takes 5 pounds?

The rule of three is:

9 pounds - 3 feet

5 pounds - x feet

Applying cross multiplication:

$9x = 3(5)$

$x = \frac{15}{9}$

$x = 1.67$

The board that requires 5 pounds of pressure to break is 1.67 inches long.

To learn more about proportions, you can take a look at https://brainly.com/question/24372153