Answer:
Value of coefficient of kinetic friction is 0.26 .
Explanation:
Given:
Mass of wooden crate, m = 12.5 kg.
Horizontal force to keep the block moving with constant velocity, F = 32.0 N.
Since, the block is moving with constant velocity.
So, net force experience by it is zero.
Therefore, fore of friction is equal to applied force.
Now, force of friction , 
( here 
is coefficient of kinetic friction and N is normal force)
Therefore, 
Now, both forces are equal.
The value of coefficient of kinetic friction is 0.26 .
Hence, it is the required solution.
The complete answer contains the answer choices.
This is the complete question:
Atoms of which element react spontaneously with Mg2+(aq)? (1)chromium
(2)barium
(3)iron
(4)zinc
Answer: option 2. barium.
Explanation.
1) Mg ²⁺ (aq) is the aquous cation of the metal Mg.
2) Only a metal more reactive than Mg will be able to exchange with it the oxidation states.
3) Mg is an earth alkalyne metal (group 2 of the periodic table). The metals from this group are more reactive than the metals in the groups to its right: 3, 4, 5, 6, 7, ... Only the alkalyne metals (those in group 1) are more reactive than the earth alkalyne metals.
4) Of the list, barium is the only alkalyne metal, so it is more reactive than Mg and will be able to deliver 2 electrons to transform the cations Mg²⁺ into Mg while the very Ba will become Ba²⁺.
5) Chromium, iron and zinc are transition metals, so less metallic (reactive) than Mg.
Answer:
a. Kp=1.4
b.Kp=2.0 * 10^-4
c.Kp=2.0 * 10^5
Explanation:
For the reaction
A(g)⇌2B(g)
Kp is defined as:
The conditions in the system are:
A B
initial 0 1 atm
equilibrium x 1atm-2x
At the beginning, we don’t have any A in the system, so B starts to react to produce A until the system reaches the equilibrium producing x amount of A. From the stoichiometric relationship in the reaction we get that to produce x amount of A we need to 2x amount of B so in the equilibrium we will have 1 atm – 2x of B, as it is showed in the table.
Replacing these values in the expression for Kp we get:
Working with this equation:
This last expression is quadratic expression with a=4, b=-(4+Kp) and c=1
The general expression to solve these kinds of equations is:
(equation 1)
We just take the positive values from the solution since negative partial pressures don´t make physical sense.
Kp = 1.4
With x1 we get a partial pressure of:
Since negative partial pressure don´t make physical sense x1 is not the solution for the system.
With x2 we get:
These partial pressures make sense so x2 is the solution for the equation.
We follow the same analysis for the other values of Kp.
Kp=2*10^-4
X1=0.505
X2=0.495
With x1
Not sense.
With x2
X2 is the solution for this equation.
Kp=2*10^5
X1=50001
With x1
Not sense.
With x2
X2 is the solution for this equation.
The answer is true the si base unit for mass is the gram
