Answer:
b= 2.14 m
Explanation:
Given that
Weight of the board ,wt = 40 N
Wight of the first children , wt₁=500 N
Weight of the second children ,wt₂ = 350 N
The distance of the 500 N child from center ,a= 1.5 m
lets take distance of the 350 N child from center = b m
Now by taking the moment about the center of the board
We know that moment = Force x Perpendicular distance from the force
wt₁ x a = wt₂ x b
500 x 1.5 = 350 x b
b= 2.14 m
Therefore the distance of the 350 N weight child from the center is 2.14 m.
 
        
             
        
        
        
The answer should be B :)
        
                    
             
        
        
        
7 A.M 
I’m pretty sure that’s it
        
             
        
        
        
When solid material expands in response to an increase in temperature (thermal expansion), it can increase in length in a process known as linear expansion. for an example application of expansion and contraction. 
examples = 
(1) Changing of shape and dimensions of objects such as doors. 
(2) Wall collapsing due to bulging. 
(3) Cracking of glass tumbler due to heating. 
(4) Bursting of metal pipes carrying hot water or steam are some of the disadvantages of thermal expansion of matter.
        
             
        
        
        
Though the hot cocoa would have a higher temperature, the lake would have more thermal energy because it has more molecules with a greater total internal energy.