Explanation:
The capacitance in two parallel-plate capacitors is:

For air, we have 
For plastic, we have 
Hence:

a) Recall that the potential difference between the plates is the same (
). The electric field is given by:

The potential difference is defined as:

Replacing:

b) The energy is defined as:

So:

Answer:
E. 0.25
Explanation:
Given that
Angular speed ω = 3.5 rad/s
Distance ,r= 0.2 m
Lets take mass of dust bunny = m
We know that
Radial force F = m ω² r
The friction force on the dust bunny Fr
Fr= μ m g
To getting slung off dust bunny from disk
m ω² r = μ m g
ω² r = μ g
3.5² x 0.2 = μ x 10 ( take g =10 m/s²)
μ = 0.245
μ = 0.25
Therefore answer is E
E. 0.25
Answer:
9.4 m/s
Explanation:
According to the work-energy theorem, the work done by external forces on a system is equal to the change in kinetic energy of the system.
Therefore we can write:

where in this case:
W = -36,733 J is the work done by the parachute (negative because it is opposite to the motion)
is the initial kinetic energy of the car
is the final kinetic energy
Solving,

The final kinetic energy of the car can be written as

where
m = 661 kg is its mass
v is its final speed
Solving for v,

I think it’s cannot be determined
Explanation:
It is given that,
Mass of the runner, m = 70 kg
Length of the tendon, l = 15 cm = 0.15 m
Area of cross section, 
Part A,
Let the runner's Achilles tendon stretch if the force on it is 8.0 times his weight, F = 8 mg
Young's modulus for tendon is, 
The formula of the Young modulus is given by :



Part B,
The fraction of the tendon's length does this correspond is given by :


Hence, this is the required solution.