The continent of Antartica is located at the bottom of the world. the South Pole is at its center. Antarctica is the coldest and windiest place on earth. It is covered with ice up to 3 miles thick. Very few plants and animals can survive here, but penguins, fish, and seals live on the coast and in the seas. No people live on Antarctica permanently, but scientists and tourists visit.
Answer:
As the temperature of materials increase, the objects find a phenomenon called change of phase.
This means that if you give enough heat to a liquid, this can change of state from liquid state to gas state (the water evaporates)
So the water in the pan reaches the evaporation temperature (around 100°C) and it starts to evaporate, this is why the water on the outside begins to "dry"
Answer:
180° C
Explanation:
First we start by finding the area of the stopper.
A = πd²/4, where d = 1.5 cm = 0.015 m
A = 3.142 * 0.015² * ¼
A = 1.767*10^-4 m²
Next we find the force on the stopper
F = (P - P•)A, where
F = 10 N
P = pressure inside the tube,
P• = 1 atm
10 = (P - 101325) * 1.767*10^-4
P - 101325 = 10/1.767*10^-4
P - 101325 = 56593
P = 56593 + 101325
P = 157918 Pascal
Now, remember, in an ideal gas,
P1V1/T1 = P2V2/T2, where V is constant, then we have
P1/T1 = P2/T2, and when we substitute the values, we have
101325/(273 + 18) = 157918/ T2
101325/291 = 157918/ T2
T2 = (157918 * 291)/101325
T2 = 453 K
T2 = 453 - 273 = 180° C
Answer:
<em>60008.4 J</em>
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Explanation:
The mass of each kid = 30 kg
mass of the cart = 20 kg
The speed of the cart down the hill = 30 km/hr = 30 x 1000/3600 = 8.33 m/s
The height of the hill = 80 m
The potential energy of the boys at the top of the hill = mgh
where
m is the total mass of the kids and the cart = (30 x 2) + 20 = 80 kg
g is the acceleration due to gravity = 9.81 m/s^2
h is their height above the ground = 80 m (on the top of the hill)
substituting, we have
potential energy PE = 80 x 9.81 x 80 = 62784 J
At an instance at the bottom of the hill
their kinetic energy = 
where
v is their velocity = 8.33 m/s
m is their total mass = 80 kg
substituting, we have
kinetic energy KE = 
= 2775.6 J
Total work done on the cart is equal to the energy lost by the cart when it reached the bottom of the hill
work done by friction = PE - KE = 62784 - 2775.6 = <em>60008.4 J</em>
