contestada

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?

Respuesta :

Answer:

21 pounds

Step-by-step explanation:

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

f = [tex]\frac{k}{l}[/tex] ← k is the constant of variation

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

15 = [tex]\frac{k}{7}[/tex] ( multiply both sides by 7 )

105 = k

f = [tex]\frac{105}{l}[/tex] ← equation of variation

When l = 5 , then

f = [tex]\frac{105}{5}[/tex] = 21 pounds
21 pounds is this answer for the problems

Otras preguntas