Answer:
In Step 5, you will calculate H+/OH– ratios for more extreme pH solutions. Find the concentration of H+ ions to OH– ions listed in Table B of your Student Guide for a solution at a pH = 2. Then divide the H+ concentration by the OH– concentration. Record these concentrations and ratio in Table C.
What is the concentration of H+ ions at a pH = 2?
0.01   mol/L  
What is the concentration of OH– ions at a pH = 2?
0.000000000001   mol/L  
What is the ratio of H+ ions to OH– ions at a pH = 2?
10,000,000,000 : 1
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I LITERALLY spent 40 MINUTES trying to figure out this question, so please, use my VERY CORRECT answers!
I hope this helps!
 
        
             
        
        
        
Answer:
13 m/s 
Explanation:
I assume we are ignoring friction.
The boy's PE will all be converted to KE at the bottom of the hill.
to find PE = mgh   we need to know h
    h = 50 sin 10 = 8.68 meters
      then:    PE = 20 * 9.81 * 8.68 =<u> 1703.49</u> j 
KE = 1/2 m v^2 = <u>1703 .49</u> 
             v = 13 m/s 
 
        
             
        
        
        
Explanation:
Below is an attachment containing the solution.