Answer:

Explanation:
From the question we are told that:
Fermi energy of conduction electrons 
Generally the equation for Fermi energy is mathematically given by



Where
h= Planck's constant




Answer:
The near point of an eye with power of +2 dopters, u' = - 50 cm
Given:
Power of a contact lens, P = +2.0 diopters
Solution:
To calculate the near point, we need to find the focal length of the lens which is given by:
Power, P = 
where
f = focal length
Thus
f = 
f =
= + 0.5 m
The near point of the eye is the point distant such that the image formed at this point can be seen clearly by the eye.
Now, by using lens maker formula:

where
u = object distance = 25 cm = 0.25 m = near point of a normal eye
u' = image distance
Now,



Solving the above eqn, we get:
u' = - 0.5 m = - 50 cm
Her average speed per hour, was 42.5 miles per hour
Answer:

Explanation:
= Mass of the Earth = 5.972 × 10²⁴ kg
G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²
r = Radius of Earth = 6371000 m
m = Mass of person
The force on the person will balance the gravitational force

The acceleration that the Earth will feel is 
Answer:
It takes 266 seconds to melt the ice.
Explanation:
Given data
- Power of the microwave oven (P): 125 Watt
- Heat supplied to the ice (Q): 33,200 Joule
- Time for the melting (t): to be determined
In order to determine the time required to melt the ice, we can use the following expression.
P = Q/t
t = Q / P = 33,200 J/ 125 W = 266 s
It takes 266 seconds to melt the ice.