is the surest test which confirms that the given piece of the object is a magnet. 1.Rotation
2.Repulsion
3.None of these
4.Refraction

2. Repulsion

Explanation:

number two is the answer

Repulsion is the surest test which confirms that the given piece of the object is a magnet.

what was the acceleration of the 2 kg cart?

⇒ 16.0 cm/s2

what was the acceleration of the 4 kg cart?

⇒ 8.1 cm/s2

what was the acceleration of the 6 kg cart?

⇒ 5.3 cm/s2

the temperature and the pressure affect solubility. temperature affects by changing the properties of the solvent. the increase in pressure increases solubility, the decrease in pressure decreases solubility.