In kickboxing, it is found that the force, f, needed to break a board, varies inversely with the length, l, of the board. If it takes 15 pounds of pressure to break a board that is 7 feet long, how many pounds of pressure will it take to break a board that is 5 feet long?

21 pounds

Step-by-step explanation:

Given that f varies inversely with l then the equation relating them is

f = ← k is the constant of variation

To find k use the condition f = 15 when l = 7, then

15 = ( multiply both sides by 7 )

105 = k

f = ← equation of variation

When l = 5 , then

f = = 21 pounds

answer:   28.56 feet (approx)

step-by-step explanation:

since, triangle abc has measure of angle c equal to 55 degrees, measure of angle abc equal to 90 degrees, and length of bc equal to 20 feet.

we have to find out the measurement of segment ab.

therefore, tan 55° =

but bc = 20 feet.

⇒ tan 55 ° =  

⇒ ab = 20 × tan 55 °

⇒ ab = 20 × 1.42814800674

⇒ ab = 28.5629601348   ≈ 28.56 feet

she was supposed to add the hours(38.5) and multiply the amount of money she earned(7.50) resulting in $288.75 .

correct me if i'm wrong and if it is i'm truly sorry.