Answer:
Making the lumber thick will make it stiff, which seems good. On the other hand, with thicker lumber, differences in expansion on the two faces have more leverage to make the lumber move.
 
        
             
        
        
        
When driving on roads that may be slippery, do not make any sudden changes in speed or direction. Option D is correct.
<h3 /><h3>What is a slippery surface?</h3>
The slick road sign serves as a warning.  When the road is wet or ice, drivers should use extra caution and reduce their speed. When the weather is bad, avoid making any rapid changes in direction.
When driving on roads that may be slippery, do not make any sudden changes in speed or direction. It may cause accident because the vehicle can lose their balance.
Hence, option D is correct.
To learn more about the slippery surface, refer to the link;
brainly.com/question/1953680
#SPJ1
 
        
             
        
        
        
Answer:
Extraneous
Explanation:
Extraneous variables are any variables that you are not intentionally studying in your experiment or test
 
        
             
        
        
        
<span>Answer:
Using 1/f = 1/d' + 1/d ...(where d' object distance and d is image distance)
1/4 = 1/7 + 1/d
1/4 - 1/7 = 1/d
3/28 = 1/d
d = 28/3
d = 9.33 cm</span>
        
             
        
        
        
Answer:
Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space.
Explanation: