In the first case, the force acting on the spring is the weight of the mass:

This force causes a stretching of

on the spring, so we can use these data to find the spring constant:

In the second case, the first mass is replaced with a second mass, whose weight is

And since we know the spring constant, we can calculate the new elongation of the spring:
the answer is definitely A.
Answer: The first electromagnet has a more powerful current than
the second
Explanation:
Since the two electromagnets contain the same types of magnets and wires. If the magnet In the first moves much faster than the second. Therefore:
The first electromagnet has a more powerful current than the second
Because the induced EMF is proportional to the induced current.
Where the induced EMF depends on the speed of the magnet according to the formula below
EMF = BVL
So, increase in speed of the magnet will cause more powerful induced current and emf
120 is your answer. 120 mL = 120 cm^3
Answer:
1. The magnet is magnetic and can attract iron articles.
2. The magnet has magnetic poles. Each magnet has two kinds of poles: N pole and S pole. They are in pairs.
3. Temporary magnet and permanent magnet: when the ferromagnetic material is magnetized, it is easy to lose the magnetic property, which is called temporary magnet (for example: iron); when the ferromagnetic material is magnetized, it is not easy to lose the magnetic property, which is called permanent magnet (for example: steel).
4. When two magnets are close to each other, the same poles will repel and push away from each other, and the different poles will attract and stick to each other. Therefore: the same pole repels each other, the different pole attracts each other.
5. The attraction of a magnetic object is called magnetism. An object is surrounded by a magnetic material. The area affected by the magnetic force is called the magnetic field.