Answer:

Explanation:
Δ
- Δ is the difference in velocity before and after a given time. is the difference in velocity before and after a given time.
 is the acceleration of the object during this time. is the acceleration of the object during this time.
 is time is time
 is another way to write this equation.
 is another way to write this equation. 
- The Δ symbol represents "the difference between the initial and final values of a magnitude or vector", so Δ 

- I rearranged this equation to solve for  , but this is a step that you don't need to take, it's just good to get in the habit of doing this. , but this is a step that you don't need to take, it's just good to get in the habit of doing this.
- Plug in the given values. Note that our final velocity is  , because the car travels until at <em>rest</em>. , because the car travels until at <em>rest</em>.
![a=\frac{v_f-v_i}{t}\\a=\frac{(0)-[(17.1\frac{miles}{hour} )(\frac{hour}{3600s})(\frac{1609.34m}{mile})]}{9.7s}](https://tex.z-dn.net/?f=a%3D%5Cfrac%7Bv_f-v_i%7D%7Bt%7D%5C%5Ca%3D%5Cfrac%7B%280%29-%5B%2817.1%5Cfrac%7Bmiles%7D%7Bhour%7D%20%29%28%5Cfrac%7Bhour%7D%7B3600s%7D%29%28%5Cfrac%7B1609.34m%7D%7Bmile%7D%29%5D%7D%7B9.7s%7D)
- Our initial velocity is in mph, something not in standard units, so if not changed, you will get an incorrect answer. What you need to do is cancel out the units your prior value had using division and multiplication, and at the same time multiply and divide the correct numbers and units into your equation. Or look up a converter.
![a=\frac{(0)-[(17.1\frac{miles}{hour} )(\frac{hour}{3600s})(\frac{1609.34m}{mile})]}{9.7s}\\a=\frac{0m/s-7.6m/s}{9.7s} \\a=\frac{-7.6m/s}{9.7s}](https://tex.z-dn.net/?f=a%3D%5Cfrac%7B%280%29-%5B%2817.1%5Cfrac%7Bmiles%7D%7Bhour%7D%20%29%28%5Cfrac%7Bhour%7D%7B3600s%7D%29%28%5Cfrac%7B1609.34m%7D%7Bmile%7D%29%5D%7D%7B9.7s%7D%5C%5Ca%3D%5Cfrac%7B0m%2Fs-7.6m%2Fs%7D%7B9.7s%7D%20%5C%5Ca%3D%5Cfrac%7B-7.6m%2Fs%7D%7B9.7s%7D)
- if you converted correctly, your answer for  will be ≅ will be ≅ . .
- Now divide. Notice that the units for acceleration are  or <em>meters per second, per second</em>. or <em>meters per second, per second</em>.

- Our final answer is <em>negative </em>because the car is <em>slowing down</em>. Do not square this answer as the square symbol only applies to the units, not the magnitude.
 
        
                    
             
        
        
        
I beleive that the answer is B.
        
             
        
        
        
if in 1 second the jet goes 428 meters and you want to know how long it takes to go 237 meters you just divide 237/428  
it can be written like this  
_1_ = __x__  
428 237  
cross multiply  
428 times x = 1 times 237  
428x=237  
divide by 428 on both sides  
x= 237/428  
x=0.5537 seconds