The correct answer is option b, 63.6 kPa
Given,
The diameter of the heel, d=7 cm=0.07 m
The mass of the child, m=25 kg
The pressure is given by the ratio of the force to the area through which the force is applied.
The force applied on the floor by the child is equal to its weight.
Thus the pressure applied on the floor by the child is given by,
Where A is the area of the cross-section of the heel.
On substituting the known values,
Thus the pressure applied on the floor by the heel is 63.6 kPa
Answer:
Physical Properties of Carbon:
Carbon is a unique element. It occurs in many forms. Some examples of the pure form of carbon are coal and soot.
It is soft and dull grey or black in colour.
One of the most important compounds of carbon is the charcoal, which is formed when carbon is heated in the absence in of air.
It occurs in a number of allotropic forms. Allotropes are nothing but forms of an element with varying physical as well as chemical properties.
The density of the different forms of carbon depends upon the origin of these elements. You will find some forms of carbon which are pure and some forms which are not pure like coal which is the mixture of both carbon and hydrogen.
Chemical Properties of Carbon
Carbon compounds generally show 4 reactions, they are
Combustion reaction
Oxidation reaction,
Addition reactions
Substitution reaction.
As we all know that carbon in all forms needs oxygen, heat, and light and forms carbon dioxide. When it is burned in air to give carbon dioxide, it is called as combustion.
Let us get the concept of this using some examples when it is burnt in the air: When methane CH4 is burnt in the presence of oxygen it gives us carbon dioxide, heat, and light.
Explanation:
Answer:
D) sudden and irresistible on sets of sleep during normal waking periods
Explanation:
D because Narcolepsy (sudden and irresistible on sets of sleep during normal waking periods) is a part of insomnia
Answer:
a) x₀ = - 2 m , b) y = 4.47 m
Explanation:
A wave travels in the middle with constant speed, let's use the equation of uniform motion
v = d / t
t = d / v
The distance to the first listeners, see attached
d₁ = x₀-x
t = (x₀ +7) / v
The distance to the second listener
d₂ = x - x₀
t = (+ 3- x₀) / v
As the wave arrives at the same time, we can equal the two equations
(x₀ +7) / v = (3 -x₀) / v
x₀ + 7 = 3 - x₀
2 x₀ = 3 - 7
x₀ = -4/2
x₀ = - 2 m
b) The time it takes for the wave to reach the listeners of the x-axis, where the speed of sound is 340 m / s
t = 5/340
t = 0.0147 s
Let's look for the distance the wave travels for the listener axis and
v = d₃ / t
d₃ = v.t
d₃ = 340 * 0.0147
d₃ = 5 m
For the distance component we use the Pythagorean triangle
d₃² = x₀² + y²
y² = d₃² - x₀²
y = √ (d₃² -4)
y = √ (5² -4)
y = 4.47 m
