Answer:
a) x = (0.0114 ± 0.0001) in
, b) the number of decks is 5
Explanation:
a) The thickness of the deck of cards (d) is measured and the thickness of a card (x) is calculated
         x = d / 52
         x = 0.590 / 52
         x = 0.011346 in
Let's look for uncertainty
        Δx = dx /dd Δd
        Δx = 1/52 Δd
        Δx = 1/52  0.005
        Δx = 0.0001 in
The result of the calculation is
         x = (0.0114 ± 0.0001) in
b) You want to reduce the error to Δx = 0.00002, the number of cards to be measured is
            #_cards = n 52
The formula for thickness is
            x = d / n 52
Uncertainty
           Δx = 1 / n 52  Δd
          n = 1/52 Δd / Δx
          n = 1/52 0.005 / 0.00002
          n = 4.8
Since the number of decks must be an integer the number of decks is 5
 
        
             
        
        
        
The moon, because the acceleration due to gravity is less.
        
             
        
        
        
Answer:
1992 (Early 1990s)
Explanation:
First of all, i would like to define an extrasolar planet as a planet that orbits a start that is not our own.
The first confirmed detections of extrasolar planets occured in the early 1990s (specifically 1992, some say 1995). The name of the first extrasolar planet is widely believed to be called Dimidium or 51 Pegasi b.  
Extrasolar were searched by monitoring stars for slight dimming that might occur as unseen planets pass in front of them.
 
        
             
        
        
        
Jack------------ force of 92.5 n   eastward-------Fjack(X)=92.5 n   Fjack(Y)=0
<span>jill ------------------------------- force of 89.9 n   northeast
Fjill(X)=cos45*89.9=63.57 n
</span>Fjill(Y)=sin45*89.9=63.57 n<span>
</span>jane -----------------------------force of 163 n   southeast
Fjane(X)=cos45*163=115.26 n
Fjane(X)=-sin45*163=-115.26 n
Ftotal (X)=92.5+63.57+115.26=271.33 n
Ftotal (Y)=0+63.57-115.26=-51.69 n
Fotal=((271.33)^2+(-115.26)^2) ^0.5=294.80 n southeast
the magnitude of the net force the people exert on the donkey. is 294.80 n southeast