Answer:
Electric field = 8.6364 × 10⁶ V/m
Explanation:
Given that:
The Voltage across the cell membrane = 76.0 mV
Also, 1 mV = 0.001 V
So, Voltage = 0.076 V
Given the thickness of the membrane = 8.80 nm
Also, 1 nm = 10⁻⁹ m
So, Thickness = 8.80 × 10⁻⁹ m
The expression for electric field is shown below as:
Electric field = 8.6364 × 10⁶ V/m
Answer:
B) electrons
Explanation:
When charge is transferred by friction, induction or conduction, the charge carriers are the electrons.
In fact, protons and neutrons are found within the nucleus of the atoms, so they are tightly bound and they cannot be easily gained/given off. On the contrary, electrons are found in the electron clouds around the nucleus, so atoms can more easily gain/lose electrons, which become free and can be passed by an object to another.
The three methods of charging are:
- Friction: by rubbing two objects together, electrons may be transferred from one to another
- Induction: by moving a charged object closer to a neutral object, opposite charges in the neutral object migrate towards the opposite ends of the object, and if the object is connected to the ground, the charges of one polarity leave the object, leaving the object charged
- Conduction: by putting a charged object in contact with a neutral object, electrons can be transferred from the charged object to the neutral one
Answer:
a)η = 0.088
b) η = 0.5
Explanation:
a) The attached figure shows the P-V diagram for the process described in the exercise. According to that figure, the work during process 1-2 is equal to:
W(1-2) = -n*R*T1*ln(vi/vf) = -n*R*T1*ln(V/(V/2)) = -n*R*T1*ln(2)
the work during process 2-3 is equal to:
W(2-3) = nR*(T2-T1)
The work done during the 3-1 process equals zero, because the volume is constant. The specific heat for the molar specific heat equals:
cp = 7*R/2, where R is gas constant.
Qin = n*cp*(T2-T1) = 7*n*R/2*(T2-T1)
the efficiency of the cycle is equal to:
η = (W(1-2) + W(2,3))/Qin = (-n*R*T1*ln2 + n*R*(T2-T1))/(7*n*R/2*(T2-T1) = (2/7)*(1-(ln2/((T2/T1)-1)))
if we write the expression between volume and temperature, we have:
T2/T1 = v1/v2
T2/T1 = v/(v/2))
T2/T1 = 2
η = (2/7)*(1-(ln2/(2-1))) = 0.088
b)
The equation for efficiency of Carnot will be equal to:
η = 1-(T1/T2) = 1 - (1/2) = 0.5