Answer:
The near point is 
Explanation:
From the question we are told that
The power is 
The distance from the eye is 
The distance of the book from the eye is 
Generally the focal length of the glasses is

=> 
=> 
=> 
The object distance is evaluated as

=> 
=> 
The image distance is evaluated from lens formula as

=> 
=> 
=> 
The near point is evaluated as

=> 
=> 
Answer:
Average speed of Olympic runner will be 23.08 km/hr
Explanation:
We have given distance d = 27.3 miles
We know that 1 mile = 1.6 km
So 27.3 mile = 
Given time = 2 hour 45 minutes and 35 sec
We know that 1 hour = 60 minutes
So 45 minutes 
We also know that 1 hour = 3600 sec
So 1 sec 
So total time t =
We know that speed 
(a) The efficiency of an engine is defined as the ratio between the work done by the engine and the heat it takes in:

The engine in this problem does a work of

and it takes in

of heat, therefore its efficiency is

(b) The heat taken by the machine is 4000 J; of this amount of heat, only 1100 J are converted into useful work. This means that the rest of the heat is wasted. Therefore, the wasted heat is the difference between the heat in input and the work done by the engine:
Above information helps you bro.