Q1.
Take a spring balance and a few objects. Keep in mind that the objects should not be heavier than the maximum value of weight the spring balance can measure, otherwise it may get damaged. Suspend the objects one by one from the hook (Fig. 5.14). Read the scale for weight carefully and record your observations in the Table 5.2.
Answer
How to take the reading correctly
- Hold the balance hanging freely and check that the pointer reads zero before anything is attached.
- Suspend one object from the hook and wait until it stops swinging.
- Read the newton scale with your eye level with the pointer, so that you do not read a mark above or below the true one.
- Read to the nearest division — for this balance, to the nearest 0.2 N. Write the unit N with every entry.
Sample answer — your own readings will differ, because your objects are not the same as these.
| S.No. | Object | Weight (N) |
|---|---|---|
| 1. | Pencil box | 1.6 N |
| 2. | Partially filled water bottle | 5.0 N |
| 3. | Geometry box | 2.4 N |
| 4. | A small stone | 3.2 N |
Why the warning matters: a spring balance works only as long as the spring returns to its original length when the load is removed. Overload it and the spring stays permanently stretched — after that every reading it gives is wrong, and no amount of care in reading will fix it.
Tip: repeat Activities 5.10 to 5.12 using the mass scale on the left of the balance (Fig. 5.13) and you will have measured the mass of the same objects, in grams. Notice that you did the same experiment both times — the instrument really measures the pull of the Earth, and the gram scale simply converts it for you.