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
Answer:
Explanation:
The change in potential energy can be expressed as:
where K is a constant with a value of 
, q1 and q2 are the charges of the proton and the electron and r is the distance between them.
The charge for the proton is 
and the charge for the electron is 
.
Converting r=1.0nm to m:
Replacing values:
The average speed would be 33.29m/s.The average speed equation is:
First you will need to solve for the distance you traveled in each scenario. So we can solve this by getting the product of speed and the time traveled.
Scenario 1:
Speed = 29m/s
Time = 120s
Distance = ?
Distance = (29m/s)(120s)
= 3,480m
Scenario 2
Speed = 35m/s
Time = 300s
Distance = ?
Distance = (35m/s)(300s)
= 10,500m
Now that you have the distance of both, you can solve for your average speed.
The answer is C. Potential energy is when an object is at rest.
Kinetic is when an object is in motion.
Given : A ball of mass 40 g moving at a velocity of 4 m/s.
To find : Calculate the kinetic energy in joules ?
Solution :
The kinetic energy formula is given by,
where, v is the velocity v=4 m/s
m is the mass m=40 g
Convert g into kg,
Substitute the values,
Therefore, the kinetic energy is 0.32 Joules.
