Answer:
People have been aware of magnets and magnetism for thousands of years. The earliest records date back to ancient times, particularly in the region of Asia Minor called Magnesia-the name of this region is the source of words like magnet. Magnetic rocks found in Magnesia, which is now part of western Turkey, stimulated interest during ancient times. When humans first discovered magnetic rocks, they likely found that certain parts of these rocks attracted bits of iron or other magnetic rocks more strongly than other parts. These areas are called the poles of a magnet. A magnetic pole is the part of a magnet that exerts the strongest force on other magnets or magnetic material, such as iron. For example, the poles of the bar magnet shown in Figure 20.2 are where the paper clips are concentrated.
Given:
Momentum of the dog (p) = 120.5 kg m/s
Speed of the dog (v) = 5 m/s
To Find:
Mass of the dog (m)
Concept/Theory:

- It is defined as the quantity of motion contained in a body.
- It is measured as the product of mass of the body and it's speed.
- It is represented by p.
- It's SI unit is kg m/s
- Mathematical Representation/Equation of Momentum:

Answer:
By using equation of momentum, we get:

Mass of the dog (m) = 24.1 kg
Answer:
80.6 mV
Explanation:
Parameters given:
Number of turns, N = 115
Radius of coil, r = 2.71 cm = 0.0271m
Time taken, t = 0.133s
Initial magnetic field, Bin = 50.1 mT = 0.0501 T
Final magnetic field, Bfin = 90.5 mT = 0.0905 T
Induces EMF is given as:
EMF = [(Bfin - Bin) * N * A] / t
EMF = [(0.0905 - 0.0501) * 115 * pi * 0.0271²] / 0.133
EMF = (0.0404 * 115 * 3.142 * 0.0007344) / 0.133
EMF = 0.0806 V = 80.6 mV
Answer:
B
Explanation:
because kinetic energy is directly proportional to temperature so the hottor the object, the more kinetic energy.