Answer:
paper burned and turned into smoke...
Explanation:
When a chemical reaction has taken place that means that whatever the starting variable is, (in this case it was the paper) then it cannot go back to its original state... you can also tell if a chemical reaction has taken place if the test releases any kind of gas, if there is a temperature change, or if there is a color change. Which this time it changed from paper into smoke which is a gas
Hope This Helps
Answer:
The mass of unknown object is 8.62Kg
Explanation:
To develop this problem it is necessary to apply the equations related to the Drag force and the Force of Gravity.
For the given point, that is, the moment at which the terminal velocity is reached, the two forces equalize, that is,
By definition we know that the Drag force is defined as
Where,
Drag coefficient
Density
A =Cross-sectional Area
V = Velocity
In the other hand we have,
Where,
Mass of sphere
Mass of unknown object
Equating the two equations we have to
Re-arrange for m_2,
Our values are given by,
Replacing in the equation we have,
<em>Therefore the mass of unknown object is 8.62Kg</em>
A person runs up 40 stairs and then come down 10 steps
So total stairs upwards is given as
now here we will have total height reached
Now total energy used or mechanical work done is
Now the mechanical power is given as
The unit measurement for sound can be expressed in terms of intensity and in decibels. The intensity of sound is the measure of its power over unit area. The common unit of measurement is in decibels. This is commonly used in measuring the extent of noise. The conversion from intensity to the decibel unit is through logarithmic function. The formula is:
dB = 10 log(I/I0), where I0 is 10^-12 Watts per square meter
Substituting the values to the equation,
84 = 10log(I/10^-12)
I = 0.0002512 W/m2
In scientific notation the intensity is 2.512 x 10^-4 W/m^2.
