A curtain hangs straight down in front of an open window. A sudden gust of wind blows past the window; and the curtain is pulled
1 answer:
You might be interested in
The question is missing some parts. Here is the complete question.
An ideal gas is contained in a vessel at 300K. The temperature of the gas is then increased to 900K.
(i) By what factor does the average kinetic energy of the molecules change, (a) a factor of 9, (b) a factor of 3, (c) a factor of , (d) a factor of 1, or (e) a factor of
?
Using the same choices in part (i), by what factor does each of the following change: (ii) the rms molecular speed of the molecules, (iii) the average momentum change that one molecule undergoes in a colision with one particular wall, (iv) the rate of collisions of molecules with walls, and (v) the pressure of the gas.
Answer: (i) (b) a factor of 3;
(ii) (c) a factor of ;
(iii) (c) a factor of ;
(iv) (c) a factor of ;
(v) (e) a factor of 3;
Explanation: (i) Kinetic energy for ideal gas is calculated as:
where
n is mols
R is constant of gas
T is temperature in Kelvin
As you can see, kinetic energy and temperature are directly proportional: when tem perature increases, so does energy.
So, as temperature of an ideal gas increased 3 times, kinetic energy will increase 3 times.
For temperature and energy, the factor of change is 3.
(ii) Rms is root mean square velocity and is defined as
Calculating velocity for each temperature:
For 300K:
For 900K:
Comparing both veolcities:
For rms, factor of change is
(iii) Average momentum change of molecule depends upon velocity:
q = m.v
Since velocity has a factor of and velocity and momentum are proportional, average momentum change increase by a factor of
(iv) Collisions increase with increase in velocity, which increases with increase of temperature. So, rate of collisions also increase by a factor of .
(v) According to the Pressure-Temperature Law, also known as Gay-Lussac's Law, when the volume of an ideal gas is kept constant, pressure and temperature are directly proportional. So, when temperature increases by a factor of 3, Pressure also increases by a factor of 3.
Answer:
The second snowball hits the ground with a kinetic energy of 100 Joules
Explanation:
Given that,
From the edge of a roof you throw a snowball downward that strikes the ground with 100 J of kinetic energy. It is a case of conservation of energy.
At the highest point,
At lowest point,
From above two equation, we get :
Kinetic energy, K = 100 J
So, the second snowball hits the ground with a kinetic energy of 100 Joules. So, the correct option is (A).
Answer:
The amount of gas that is to be released in the first second in other to attain an acceleration of 27.0 m/s2 is
Explanation:
From the question we are told that
The mass of the rocket is m = 6300 kg
The velocity at gas is being ejected is u = 2000 m/s
The initial acceleration desired is
The time taken for the gas to be ejected is t = 1 s
Generally this desired acceleration is mathematically represented as
Here is the rate at which gas is being ejected with respect to time
Substituting values
=>
=>
=>
=>