Answer:

Explanation:
r = Radius = 
B = Magnetic field = 3 mT
1 mm = Distance from the surface of the wire
V = Voltage
x = Distance from the probe = 
R = Resistance
L = Length of wire = 4.5 m
Magnetic field is given by

Voltage is given by

Resistivity is given by

The resistivity of the material is
.
Pernament magnet is one that retains its magnetic properties for a long period of time. Temporary megnet only maintains its magnetism while in a magnetic field produced by permanent magnet or electric current.
Answer:
Explanation:
The heat required to change the temperature of steam from 125.5 °C to 100 °C is:

The heat required to change the steam at 100°C to water at 100°C is;

The heat required to change the temperature from 100°C to 0°C is

The heat required to change the water at 0°C to ice at 0°C is:

The heat required to change the temperature of ice from 0°Cto -19.5°C is:

The total heat required to change the steam into ice is:

b)
The time taken to convert steam from 125 °C to 100°C is:

The time taken to convert steam at 100°C to water at 100°C is:

The time taken to convert water to 100° C to 0° C is:

The time taken to convert water at 0° to ice at 0° C is :

The time taken to convert ice from 0° C to -19.5° C is:

Answer:
the energy when it reaches the ground is equal to the energy when the spring is compressed.
Explanation:
For this comparison let's use the conservation of energy theorem.
Starting point. Compressed spring
Em₀ = K_e = ½ k x²
Final point. When the box hits the ground
Em_f = K = ½ m v²
since friction is zero, energy is conserved
Em₀ = Em_f
1 / 2k x² = ½ m v²
v =
x
Therefore, the energy when it reaches the ground is equal to the energy when the spring is compressed.