Given Information:
Diameter of spherical cell = 0.040 mm
thickness = L = 9 nm
Resistivity = ρ = 3.6×10⁷ Ω⋅m
Dielectric constant = k = 9.0
Required Information:
time constant = τ = ?
Answer:
time constant = 2.87×10⁻³ seconds
Explanation:
The time constant is given by
τ = RC
Where R is the resistance and C is the capacitance.
We know that resistivity of of any material is given by
ρ = RA/L
R = ρL/A
Where area of spherical cell is given by
A = 4πr²
A = 4π(d/2)²
A = 4π(0.040×10⁻³/2)²
A = 5.026×10⁻⁹ m²
The resistance becomes
R = (3.6×10⁷*9×10⁻⁹)/5.026×10⁻⁹
R = 6.45×10⁷ Ω
The capacitance of the cell membrane is given by
C = kεoA/L
Where k = 9 is the dielectric constant and εo = 8.854×10⁻¹² F/m
C = (9*8.854×10⁻¹²*5.026×10⁻⁹)/9×10⁻⁹
C = 44.5 pF
C = 44.5×10⁻¹² F
Therefore, the time constant is
τ = RC
τ = 6.45×10⁷*44.5×10⁻¹²
τ = 2.87×10⁻³ seconds
Answer: 45 joules of energy
Explanation:
I would pick the only one that makes sense, D. optic fibers
Brainliest please
We have thatThe options that define Speed, Velocity,Acceleration.
- Speed is used to describe how fast the object is moving.
- Acceleration is the rate of change of velocity in time.
- Velocity is used to describe how fast the object is moving and tells us in which direction it is going.
Options
B,D,E
From the question we are told
Choose the correct definitions of speed, velocity, and acceleration. Check all that apply.
- Acceleration tells us in which direction the object is going. Speed is the rate of change of velocity in time.
- Acceleration is the rate of change of velocity in time.
- Velocity is used to describe changes in the movement direction of the object. Acceleration tells us how far the object will go in a certain amount of time.
- Velocity is used to describe how fast the object is moving and tells us in which direction it is going.
- Speed is used to describe how fast the object is moving.
- Velocity is the rate of change of speed in time.
Speed is used to describe how fast the object is moving and tells us in which direction it is going.
Generally
- Acceleration is the rate of change of velocity in time.
- Velocity is used to describe how fast the object is moving and tells us in which direction it is going.
- Speed is used to describe how fast the object is moving without its direction in consideration
Hence
The options that define Speed, Velocity,Acceleration.
- Speed is used to describe how fast the object is moving.
- Acceleration is the rate of change of velocity in time.
- Velocity is used to describe how fast the object is moving and tells us in which direction it is going.
Options
B,D,E
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