Please answer each question Background:

When you pull on a spring it stretches. Newton's $3^{rd}$ law says that the spring pulls back on you. The force by the $3)$ spring on you is called restoring force. If the spring is in equilibrium, this is also equal in magnitude to the force on the other end of the spring too.

Hooke's law states that extension of a spring is proportional to applied force.

If a spring obeys Hooke's law, then a graph of applied force against extension will be a straight line, whose gradient $($slope$)$ is $k$ :

The equation of the straight line is:

$FF=kk$

where:

$FF=$ stretching force applied to the spring

$kk=$ spring constant

$)=(e$ extension of the spring