The compass doesn’t give you the value of the net magnetic field, just the direction. So, how do you get the magnitude of a particular field from this? The trick is to assume the value of the Earth’s magnetic field and the direction of the compass. Let’s assume that at this location on the Earth, the magnetic field is pointing directly North with a horizontal component of about 2 x 10-5 T.
Now suppose that I do something to create a magnetic field in a known direction and perpendicular to the horizontal component of the Earth’s magnetic field. Here is an example where I put a current carrying wire right over the compass needle. Since the compass is underneath the wire, the magnetic field due to the wire will be 90° to the Earth’s magnetic field.
Take a small burning candle. ... After few minutes the candle is extinguished. As the supply of air is stopped due to glass jar the burning of candle is also stopped. This experiment proves that air supports burning.
Answer:
A. Endothermic reaction.
B. +150KJ.
C. 250KJ.
Explanation:
A. The graph represents endothermic reaction because the heat of the product is higher than the heat of the reactant.
B. Determination of the enthalpy change, ΔH for the reaction. This can be obtained as follow:
Heat of reactant (Hr) = 50KJ
Heat of product (Hp) = 200KJ
Enthalphy change (ΔH) =..?
Enthalphy change = Heat of product – Heat of reactant.
ΔH = Hp – Hr
ΔH = 200 – 50
ΔH = +150KJ
Therefore, the enthalphy change for the reaction is +150KJ
C. The activation energy for the reaction is the energy at the peak of the diagram.
From the diagram, the activation energy is 250KJ.
Water is usually used to cool down automobile engines when they get hot, yes. Therefore, that means water has a high heat capacity.
That makes the answer letter D you provided above.
D) Water has a high heat capacity.
Another example would be trying to put out a fire with a bucket of water. Usually, you can put out the fire debating on the size!
I believe the answer is a
