Sanitation can be accomplished by all of the means except
1 answer:
You might be interested in
This question is incomplete, the complete question is;
Model a hydrogen atom as a three-dimensional potential well with U₀ = 0 in the region 0 < x < L, 0 < y < L and 0 < z < L, and infinite otherwise, with L = 1.0 × 10⁻¹⁰ m.
Which of the following is NOT one of the lowest three energy levels of an electron in this model?
a. 283 eV
b. 339 eV
c. 113 eV
d. 226 eV
Answer:
the lowest three energy are; 113 eV, 225 eV, and 339 eV.
Hence Option a) 283 eV is not among the three lowest energy
Explanation:
Given the data in the question;
Three dimension cube or particle in a cubic box
the energy value is given by;
=
× π²h"² / 2ml²
where h" = h/2π and h is Planck's constant ( 6.626 × 10⁻³⁴ m² kg / s )
m is mass of electron ( 9.1 × 10⁻³¹ kg )
l is length of side of box ( 1.0 × 10⁻¹⁰ m )
for ground level ( )
so
× π²h"² / 2ml²
since h" = h/2π
× π²h² / (2π)²2ml²
so we substitute
= ( 1² + 1² + 1² ) × [ π²( 6.626 × 10⁻³⁴ )² ] / [ (2π)² × 2 × 9.1 × 10⁻³¹ kg × ( 1.0 × 10⁻¹⁰)² ]
= 3 × [ (4.333188779 × 10⁻⁶⁶) / ( 7.185072 × 10⁻⁴⁹ ) ]
= 3 × [ 6.03082165 × 10⁻¹⁸ ]
Now, we know that electric charge = 1.602 x 10⁻¹⁹
so
= 3 × [ (6.03082165 × 10⁻¹⁸) / (1.602 x 10⁻¹⁹) ]
= 3 × [ 37.645578 ]
= 112.9 ≈ 113 eV
=
× π²h² / (2π)²2ml²
we substitute
= ( 1² + 1² + 2² ) × [ 37.645578 ]
= 6 × [ 37.645578 ]
= 225.87 ≈ 226 eV
=
× π²h² / (2π)²2ml²
we substitute
= ( 2² + 2² + 1² ) × [ 37.645578 ]
= 9 × [ 37.645578 ]
= 338.8 ≈ 339 eV
Therefore, the lowest three energy are; 113 eV, 225 eV, and 339 eV.
Hence Option a) 283 eV is not among the three lowest energy
To get the total resistance in a parallel circuit, you need to remember that unlike in a series, you do not just merely add the resistances. You need to get the reciprocal first of each resistance and add them together.
After adding them, you will get the reciprocal again and then compute for the value. The problem says that there are 4 resistors in the circuit that have a resistance of 75.
Add up the numerator and copy the denominator:
Then get the reciprocal to get the total resistance:
The answer to your question then is A. 18.8.
After adding them, you will get the reciprocal again and then compute for the value. The problem says that there are 4 resistors in the circuit that have a resistance of 75.
Add up the numerator and copy the denominator:
Then get the reciprocal to get the total resistance:
The answer to your question then is A. 18.8.
Answer:
The coefficient of kinetic friction is 0.13
Explanation:
Newton's second law states that the acceleration of an object is proportional to the net force on it, the factor of proportionality is the mass. So, we can express that law mathematically as:
(1)
With F the net force, m the mass and a the acceleration of the object. In our case we're interested on what's happening to the sled, then we have to analyze the forces on it, those forces are the weight and the normal force on the vertical direction and the pulling force and frictional force in the horizontal direction. So, because (1) is a vector equation we can express that in their vertical (y) and horizontal (x) components:
(2)
(3)
On y we have that the acceleration is zero because the sled is not moving upward or downward, remember that the net force on y is the weight (W) pointing downward and the normal force pointing upward:
Following the convention that positive is upward and negative downward, W=mg=(755)(-9.81):
(4)
Now on the x direction we have the sum of the forces is the pulling force (T) and friction force (f)
Choosing the direction where the horse is pulling F=1988N and the acceleration should be positive too, then:
The negative sign means it's in the opposite direction the horse is pulling
The frictional force is related with the coefficient of kinetic friction in the next way:
with μk the coefficient of kinetic friction, and n the normal force that we already found on (4), so we simply solve the last equation for μk: