Answer:
The right option is (d) substance undergoing a change of state
Explanation:
Latent Heat: Latent heat is the heat required to change the state of a substance without change in temperature. Latent heat is also known as hidden heat because the heat is not visible. The unit is Joules (J).
Latent heat is divided into two:
⇒ Latent Heat of fusion
⇒ Latent Heat of vaporization.
Latent Heat of fusion: This is the heat energy required to convert a substance from its solid form to its liquid form without change in temperature. E.g (Ice) When ice is heated, its temperature rise steadily until a certain temperature is reached when the solid begins to melts.
Latent Heat of vaporization: This is the heat required to change a liquid substance to vapor without a change in temperature. The latent heat depend on the mass of the liquid and the nature of the liquid. E.g When water is heated from a known temperature its boiling point (100°C) When more heat is supplied to its boiling temperature, it continue to boil without a change in temperature.
From The above, Latent heat brings about a change of state of a substance at a steady temperature.
The right option is (d) substance undergoing a change of state
Answer:
(177.94 ± 3.81) cm^2
Explanation:
l + Δl = 21.7 ± 0.2 cm
b + Δb = 8.2 ± 0.1 cm
Area, A = l x b = 21.7 x 8.2 = 177.94 cm^2
Now use error propagation
So, the area with the error limits is written as
A + ΔA = (177.94 ± 3.81) cm^2
The amount of power change if less work is done in more time"then the amount of power will decrease".
<u>Option: B</u>
<u>Explanation:</u>
The rate of performing any work or activity by transferring amount of energy per unit time is understood as power. The unit of power is watt
Here this equation showcase that power is directly proportional to the work but dependent upon time as time is inversely proportional to the power i.e as time increases power decreases and vice versa.
This can be understood from an instance, on moving a load up a flight of stairs, the similar amount of work is done, no matter how heavy but when the work is done in a shorter period of time more power is required.
Answer:
2.5 ms^-2
Explanation:
acceleration
= (final velocity - initial velocity)/time
= [(40m/s) - (20m/s)]/8s
= (20m/s)/8s
= 5/2 m/s²
= 2.5 m/s²
= 2.5 ms^-2
