Question

17 multiple choice 1 point hooks law says that the force required to stretch a spring is proportional to the distance stretched. if a force of 18 lb is required to stretch a spring 6 in., how much force is required to stretch the spring 15 in.? 7 lb 55 lb 35 lb 45 lb 18 lb 18 multiple choice 1 point solve the formula (area of a triangle) $a=\frac{1}{2}bh$ for the letter $b$. $b = \frac{2h}{a}$ $b = 2ah$ $b=\frac{a}{2h}$ $b=\frac{h}{2a}$ $b=\frac{2a}{h}$

Explanation:

Question 17

Step1: Find the proportionality constant

Since force $F$ is proportional to distance $d$, we have $F = kd$. Given $F = 18$ lb and $d = 6$ in, we find $k=\frac{F}{d}=\frac{18}{6}=3$ lb/in.

Step2: Calculate the new force

When $d = 15$ in, using $F=kd$, we substitute $k = 3$ lb/in and $d = 15$ in. So $F=3\times15 = 45$ lb.

Step1: Isolate $b$ in the formula $A=\frac{1}{2}bh$

Multiply both sides of the equation by 2 to get $2A=bh$. Then divide both sides by $h$ (assuming $h
eq0$) to solve for $b$. So $b = \frac{2A}{h}$.

Answer:

D. 45 lb

Question 18