Answer:
The answer to your question is:
a)  t1 = 2.99 s ≈ 3 s
b)  vf = 39.43 m/s
Explanation:
Data
vo = 10 m/s
h = 74 m
g = 9.81 m/s
t = ?   time to reach the ground
vf = ?   final speed
a)    h = vot + (1/2)gt²
      74 = 10t + (1/2)9.81t²
      4.9t² + 10t -74 = 0                  solve by using quadratic formula
    
    t = (-b ± √ (b² -4ac) / 2a
    t = (-10 ± √ (10² -4(4.9(-74) / 2(4.9)
    t = (-10 ± √ 1550.4 ) / 9.81
   t1 = (-10 + √ 1550.4 ) / 9.81               t2 = (-10 - √ 1550.4 ) / 9.81
   t1 = (-10 ± 39.38 ) / 9.81                    t2 = (-10 - 39.38) / 9.81
    t1 = 2.99 s ≈ 3 s                               t2 = is negative then is wrong there are 
                                                                    no negative times.
b) Formula vf = vo + gt
                   vf = 10 + (9.81)(3) 
                   vf = 10 + 29.43
                   vf = 39.43 m/s
 
        
             
        
        
        
E                  S                                                               *
The "E" represents Earth, "S" represent Sun, and the "*" represents the nearest star(which is Proxima Centauri).
The main thing to worry about here is units, so ill label everything out.
D'e,s'(Distance between earth and sun) = .<span>00001581 light years
D'e,*'(Distance between earth and Proxima) = </span><span>4.243 light years
Now this is where it gets fun, we need to put all the light years into centimeters.(theres alot)
In one light year, there are </span>9.461 * 10^17 centimeters.(the * in this case means multiplication) or 946,100,000,000,000,000 centimeters.
To convert we multiply the light years we found by the big number.
D'e,s'(Distance between earth and sun) = 1.496 * 10^13 centimeters<span>
D'e,*'(Distance between earth and Proxima) = </span><span>4.014 * 10^18 centimeters
</span>
Now we scale things down, we treat 1.496 * 10^13 centimeters as a SINGLE centimeter, because that's the distance between the earth and the sun. So all we have to do is divide (4.014 * 10^18 ) by (<span>1.496 * 10^13 ).
Why? because that how proportions work.
As a result, you get a mere 268335.7 centimeters.
To put that into perspective, that's only about 1.7 miles
A lot of my numbers came from google, so they are estimations and are not perfect, but its hard to be on really large scales.</span>
        
             
        
        
        
Answer:
Kinematics is the study of motion.
 
        
                    
             
        
        
        
Answer:
.00135 j
Explanation:
K.E. = 1/2   m  v^2 
        = 1/2 * .03 * .3^2 = .00135 j
 
        
             
        
        
        
Answer:
Expression of work done is

Work done to move the sled is given as 187.2 J
Explanation:
As we know that the formula of work done is given as

here we know that
F = 12.6 N
d = 15.4 m

so we will have

