When you put an object on a spring balance, what do you measure ?

When you put an object on a spring balance, you measure its weight. The spring balance works on the principle of Hooke's Law, which states that the force needed to extend or compress a spring by some distance is proportional to that distance.

Here are the steps:

1. First, you need to calibrate the spring balance. This is usually done by adjusting the pointer to the zero mark without any load.

2. Next, hang the object you want to measure from the hook on the bottom of the spring balance.

3. The object will pull down on the hook due to the force of gravity, stretching the spring inside the balance.

4. The spring will stretch until the force of the spring (which is trying to contract) is equal to the weight of the object (which is trying to stretch the spring).

5. The balance has a scale along the side. The amount the spring stretches (and thus the position of the pointer) will indicate the weight of the object.

6. Read the weight directly from the scale. The unit of measurement will depend on the specific spring balance you are using. It could be in Newtons (N), which is a measure of force, or in kilograms (kg), which is a measure of mass.

Remember, the spring balance measures the weight of the object, not its mass. Weight is the force exerted by gravity on the object, while mass is the amount of matter in the object. The two are related by the equation Weight = Mass x Gravity.