## Compressing a Spring

Consider a helical compression spring has a free length of 300 mm and a spring constant of 50 N/mm. What force is required to compress the spring to a length of 200 mm?

##
__
__**Hint**

**Hint**

The force in a spring is:

$$$F_s=k\delta $$$

where
$$k$$
is the spring constant, and
$$\delta$$
is the change in spring length from the un-deformed spring length.

##
__
__**Hint 2**

**Hint 2**

$$$\delta=free\:length-compressed\:length$$$

The force in a spring is:

$$$F_s=k\delta $$$

where
$$k$$
is the spring constant, and
$$\delta$$
is the change in spring length from the un-deformed spring length.

Since
$$\delta=free\:length-compressed\:length=300mm-200mm=100\:mm$$
, the required force is:

$$$F_s=(50\frac{N}{mm})(100mm)=5,000\:N$$$

5,000 N