Answer:
a. 960 W b. One 1 kW room heater
Explanation:
a. The rate of heat conduction P = kA(T₂ - T₁)/d where k = 2 × 0.040 W/m-K = 0.080 W/m-K since the thermal conductivity of glass wool is 0.040 W/m-K and that of the material is twice the thermal conductivity of glass wool, A = area of walls = 120 m², T₁ = outside surface temperature = 5.0 °C, T₂ = inside surface temperature = 18.0 °C and d = thickness of wall = 13.0 cm = 0.13 m
P = kA(T₂ - T₁)/d
= 0.080 W/m-K × 120 m²(18.0 °C - 5.0 °C)/0.13 m
= 9.6 Wm/K × 13 K/0.13 m
= 124.8 Wm/0.13 m
= 960 W
b. The number of 1 kW room heater required will be
n = rate of heat conduction/power of one room heater = 960 W/ 1 kW = 960 W/1000 W = 0.96 ≅ 1
So we need only one 1 kW room heater.
Answer:
Spring tide is a tide with largest difference between the high and tide and the low tide on the earth on a solar day.
Neap tide is the tide with the least difference between the high and low tides on the earth in a solar day.
Explanation: Tide is the rise or fall in the level of water bodies which is easily detectable on the shore of the water bodies. This rise and fall is caused by the gravitational pull of the moon and sun in resultant.
Gravitational force between the 2 masses is mathematically given as:
where:
- G= gravitational constant =
- =mass of body 1
- = mass of body 2
- r= distance between the center of the masses.
The water on the earth acts as a membrane sue to the gravity of earth and its own surface tension.
During spring tide the earth, the moon and the sun are in a starlight line developing a greater net force on the earth due to which the membrane of the water present on the earth gets stretched by the maximum force in such condition when it is a new moon day or a full moon day.
During Neap tide the moon, and the sun are at right angles with respect to the earth developing a lesser net force on the earth due to which the membrane of the water present on the earth gets a lesser pull by the force components in such condition when it is a first quarter moon or a third quarter moon .
Answer:
17.71 kgm²s⁻¹
Explanation:
<em>Angular momentum </em>is the rotational momentum , which is quite similar to linear momentum.main difference is that here we consider a rotational motion.
*The total angular momentum of a closed system remains constant.
by definition ,
angular momentum = moment of inertia (I) × angular velocity (ω)
where
<em>ω = 2π × frequency (f)</em> = 2π × 6
<em>angular momentum = 0.47 × 12π = 17.71 kgm²s⁻¹</em>
Answer:
A. polymerization
Explanation:
Synthetic plastics are made by linking many simple carbon molecules together to form much larger molecules. This process is called polymerization.
Synthetic or artifical giant molecules consists of synthetic polymers such as plastics, elastomers etc. They are made up of simple monomers which links to form the complex and giant structure.
Monomers are the simplest unit of polymers. Polymers have very great sizes. The size mkaes their structure quite complex. This makes the molecules more disposed in a regular pattern with respect to one another.
The complexity of structure and the attendant effects accounts for the properties and uses that makes synthetic molecules very unique. For example, plastics can be extruded as sheets, pipes and or moulded into other objects.
If I've understood it correctly, the right one should look like this: In most cultures, the difference between the majority viewpoint and the minority viewpoint is that the majority group is made to feel normal and the minority group is made to feel divergent.