Question

3 imagine that you want to collect extra nails and screws from a construction site. to do this, you attach a magnet to the end of a stick. unfortunately, your tool doesn’t pick up any of the nails or screws on the ground. what two changes could you make to improve it? use a larger magnet use a stronger magnet hold the magnet closer to the ground hold the magnet farther from the ground

Explanation:

To improve the tool's ability to pick up nails/screws, we analyze magnetic force factors:

1. Use a larger magnet: A larger magnet has a bigger surface area and stronger magnetic field (due to more magnetic material), increasing the chance to attract metal objects.
2. Use a stronger magnet: A stronger magnet has a more intense magnetic field, so it can exert a greater attractive force on ferromagnetic materials (nails/screws).
3. Hold the magnet closer to the ground: Reducing the distance between the magnet and the objects decreases the magnetic field's weakening with distance, making attraction easier.
4. Hold the magnet farther from the ground: This would weaken the magnetic force (as magnetic field strength decreases with distance), so it's incorrect.

So the two correct changes are using a larger magnet, using a stronger magnet, or holding it closer (we pick two: e.g., Use a larger magnet, Use a stronger magnet, or Use a larger magnet, Hold the magnet closer to the ground, or Use a stronger magnet, Hold the magnet closer to the ground).

Answer:

A. Use a larger magnet
B. Use a stronger magnet (or A. Use a larger magnet, C. Hold the magnet closer to the ground; or B. Use a stronger magnet, C. Hold the magnet closer to the ground)