The elements that is very good in
electrical conductivity are gold and copper: elements that is amphoteric are
copper, zinc, tin, lead, aluminum and beryllium: elements that is gaseous at
room temperature are hydrogen, nitrogen, oxygen, fluorine and chlorine: elements
that is solid at room temperature are all metal except mercury and perhaps some
unseen radioactive elements. Lastly, elements that is brittle are hydrogen,
carbon, nitrogen, oxygen, phosphorus, sulfur and selenium
Answer:
Explanation:
The magnetic field in a solenoid is
B = μ₀ N / L I
Where N is the number of turns, L the solenoid length and I the current
N = B L / μ₀ I
Let's calculate
N = 5.8 10⁻³ 0.18 / 4 π 10⁻⁷ 1
N = 8.3 102 laps
N = 831 laps
Let's find the solenoid length
For this we use a rule of proportions
L_solenoid = Turns * wire diameter
L_ solenoid = 831 * 0.41 10--3
L_solenoid = 0.3407 m
We see that two turns are needed in the wire to have a length of 0.18 m
Explanation:
For, heating purposes more the quantity of water more will be the heating. Clearly, underground heating would have more water and hence, it will have edge over the water heater system.
Moreover, for things at the same temperature, the thing with more molecules has more total kinetic energy (thermal energy) than the thing with fewer molecules. The groundwater heating system uses heat from the heat stored naturally in groundwater or aquifers. Thus, saving the cost of power required to heat in normal water heater.
Answer:
A) and B) are correct.
Explanation:
If the object is at rest, it means that no net force is exerted on it.
As the object experiences a downward gravitational force from Earth, in order to be at rest, it must experience an upward force with the same magnitude as the gravitational force on the object.
This force is supplied by the normal force, which can adopt any value in order to meet the condition imposed by Newton´s 2nd Law, and is always perpendicular to the surface on which the object is placed (in this case, the ground).
At a molecular level, this normal force is supplied by the bonded molecules of the ground that behave like small springs being compressed by the molecules of the object, exerting an upward restoring force upward on them.
So, the statements A) and B) are true.
