A diverging lens is used to permit clear vision of an object placed at infinity. The focal length of the lens is -100 cm.
<h3>What is focal length?</h3>
The focal length is half of the radius of curvature of the focal lens.
By the lens maker formula,
1/f = 1/v +1/u
where, v is the image distance and u is the object distance.
Give, the object is at infinity and the image must form at 100 cm, the the focal length will be
1/f = 1/ -100 + 1/∞ 
f = -100 cm
The focal length must be -100 cm for the diverging lens.
Learn more about focal length.
brainly.com/question/16188698
#SPJ1
 
        
             
        
        
        
Answer:
original mass of the block of ice is 38.34 gram
Explanation:
Given data 
cup mass = 150 g
ice temperature = 0°C
water mass = 210 g
water temperature = 12°C
ice melt = 2 gram
to find out 
solution 
we know here
specific heat of aluminum is c = 0.900 joule/gram °C
Specific heat of water C =  4.186 joule/gram °C
so here temperature difference is dt =  12- 0 = 12°C 
so here heat lost by water and cup are given by 
heat lost  = cup mass × c  × dt + water  mass × C × dt
heat lost  = 150 × 0.900  × 12 + 210 × 4.186 × 12
heat lost  = 12168.72 J
so
mass of ice melt here = heat lost / latent heat of fusion
here we know latent heat of fusion = 334.88 joule/gram
so 
mass of ice melt  =  12168.72 / 334.88
mass of ice melt  is 36.337554 gram
so mass of ice is here = mass of ice melt + ice melt
mass of ice  =  36.337554 + 2 
mass of ice  =  38.337554 gram
so original mass of the block of ice is 38.34 gram
 
        
             
        
        
        
<span>You experience physiological changes and a feeling of fear simultaneously. Hope this helped!</span>
        
                    
             
        
        
        
a toy/model steam engine. how it works and how to measure horse power