Well, if your question is how light affects plants,
then you would want to design an experiment that plays aruond with the amount of light a plant gets
thus the thing changing (or variable) would be amount of light
Answer:The mass of ball B is 10 kg.
Explanation;
Mass of ball A = 
Velocity of the ball A before collision:
Velocity of ball A after collision=
Mass of ball B= 
Velocity of the ball B before collision:
Velocity of ball B after collision=



The mass of ball B is 10 kg.
So we want to know what will happen if we put a magnetically soft material in a strong magnetic field. A magnetically soft material is a material whose magnetic field can easily be reversed. Those are ferromagnetic materials. Iron is such a material. When a magnetically soft material is placed into a strong magnetic field it gets its own magnetic field. But its not a permanent magnetic field, it can be changed by a different strong magnetic field.
<span>Both electric and magnetic fields exert body forces, meaning they act from a distance. The like charges and poles in both repel; positive charge repels positive and the north pole repels the north pole. For both, the opposite poles/charges attract. Finally, only magnetic fields have poles, and there are two poles, namely the south and north, so they are dipolar.
The diagram that represents all of this information correctly is the third.</span>
Resolution in this sentence refers to a solution to the problem