Hang the 100 g mass on the end of the spring by separating about three to four coils of the free end of the spring and hooking the mass to those coils. Let the mass suspend from the spring until it has reached equilibrium. 2. Hold the ruler vertically next to the mass with the centimeter side closest to the mass. Hint: You will need to support the ruler while using the stopwatch with the same hand. If the mass does not hang low enough to rest the ruler on the floor, try placing your lab kit box under the hanging mass to be used as a base. If the mass touches the floor when hung on the coils try using a higher counter top. If there is no higher counter top available try using the top of an open door. You want to make sure that you can displace the mass at least 6 cm from equilibrium and not have the mass hit the floor. Be careful and use extra tape for support. Ensure the pencil is stable before hanging any mass on it. Wear safety glasses