Answer:
Magnetic field lines never intersect each other.
They originates(from north pole) and terminates (to south pole) perpendicularly from/to the surface of magnet. Also magnetic field lines continues through the magnet.
Magnetic field is denser at the pole and becomes less dense as we move away from the poles.
Explanation:
A) Pure substances, Chemical changes
The sum of the two vectors in A, B, and C is equal to the sum of the two vectors above the line. The sum of the two vectors in D isn't.
Answer:
Explanation:
As the potential energy of the freely falling object decreases, its kinetic energy increases on account of an increase in its velocity. ... Thus, the law of conservation of energy is not violated.
Answer:
a)
, b) 
Explanation:
a) According to the First Law of Thermodinamics, the system is not reporting any work, mass or heat interactions. Besides, let consider that such box is rigid and, therefore, heat contained inside is the consequence of internal energy.

The internal energy for a monoatomic ideal gas is:

Let assume that cubical box contains just one kilomole of monoatomic gas. Then, the temperature is determined from the Equation of State for Ideal Gases:



The thermal energy contained by the gas is:


b) The physical model for the cat is constructed from Work-Energy Theorem:

The speed of the cat is obtained by isolating the respective variable and the replacement of every known variable by numerical values:


