All Solutions
Page 442: Lesson Check
– The force acting on a spring $F = 5.2 text{ N}$
– The elongation of the spring $x = 14text{ cm}$
When a spring is compressed or pulled by a given force $F$ its elongation $x$ is proportional to that force, and the coefficient is called the spring constant.
We will solve the problem by applying Hooke’s Law :
$$
begin{equation*}
F = k , x
end{equation*}
$$
Rearranging for $k$ we have:
$$
begin{equation*}
k = frac{F}{x}
end{equation*}
$$
Plugging in the numbers we get:
$$
begin{align*}
k = frac{5.2text{ N}}{0.14text{ m}} = 37.14 ; frac{text{N}}{text{m}}
end{align*}
$$
– The force acting on a spring $F = 6.1 text{ N}$
– The spring constant of the spring $k = 56 ; frac{text{N}}{text{m}}$
When a spring is compressed or pulled by a given force $F$ its elongation $x$ is proportional to that force, and the coefficient is called the spring constant.
We will solve the problem by applying Hooke’s Law :
$$
begin{equation*}
F = k , x
end{equation*}
$$
Rearranging for $x$ we have:
$$
begin{equation*}
x = frac{F}{k}
end{equation*}
$$
Plugging in the numbers we get:
$$
begin{align*}
x = frac{6.1text{ N}}{56 ; frac{text{N}}{text{m}}} approx 0.109text{ m}
end{align*}
$$
– The elongation of the spring $x = 19text{ cm}$
– The spring constant of the spring $k = 62 ; frac{text{N}}{text{m}}$
When a spring is compressed or pulled by a given force $F$ its elongation $x$ is proportional to that force, and the coefficient is called the spring constant.
We will solve the problem by applying Hooke’s Law :
$$
begin{equation*}
F = k , x
end{equation*}
$$
Plugging in the numbers we get:
$$
begin{align*}
F = 62 ; frac{text{N}}{text{m}} cdot 0.19text{ m} approx 11.8text{ N}
end{align*}
$$
$$
x_1 = frac{K}{k_1},quad x_2 =frac{F}{k_2}.
$$
The total elongation is
$$
x=x_1+x_2 = frac{F}{k_1}+frac{F}{k_2} = Ffrac{k_1+k_2}{k_1k_2}
$$
which can be rewritten as
$$
F= frac{k_1k_2}{k_1+k_2}x
$$
so this system acts as a spring of constant
$$
k=frac{k_1k_2}{k_1+k_2} = 26text{ N/m}.
$$