Answer: Sara tries turning a test tube upside down to collect a gas. 
A scientist is considered to be creative when he approaches a problem with new different ways. The conventional way is to design an experiment and take detailed notes, reading referenced studies previously done. Sara tries turning a test tube upside down to collect a gas is a creative way as Sara tries something different. 
 
        
                    
             
        
        
        
the cycle of processes by which water circulates between the earth's oceans, atmosphere and land involving precipitation as rain and snow drainage in streams and rivers and return to the atmosphere by evaporation and transpiration. 
Hope this gives you a little bit more information!
 
        
             
        
        
        
Answer:
The angular acceleration α = 14.7 rad/s²
Explanation:
The torque on the rod τ = Iα where I = moment of inertia of rod = mL²/12 where m =mass of rod  and L = length of rod = 4.00 m. α = angular acceleration of rod
Also, τ = Wr where W = weight of rod = mg and r = center of mass of rod = L/2.
So Iα = Wr 
Substituting the value of the variables, we have
mL²α/12 = mgL/2
Simplifying by dividing through by mL, we have
mL²α/12mL = mgL/2mL
Lα/12 = g/2
multiplying both sides by 12, we have
Lα/12 × 12 = g/2 × 12
αL = 6g
α = 6g/L 
α = 6 × 9.8 m/s² ÷ 4.00 m 
α = 58.8 m/s² ÷ 4.00 m 
α = 14.7 rad/s²
So, the angular acceleration α = 14.7 rad/s²
 
        
             
        
        
        
These are known as balanced forces because they will not change the motion of the object, and it will remain at rest unless forces become unbalanced- meaning they would be unequal and not opposing.