In a moving car the outside looks to be moving. however if viewed from the outside, the car appears to be moving. so motion is relative to the person observing.
        
             
        
        
        
Answer:
A
Explanation:
because thats what I put and got it right
 
        
             
        
        
        
Answer:
Explanation:
dU= dq+w
dU is change in internal energy of the system
dq is the amount heat added or released by the system which be positive or negative respectivelý
And w is the amount of work done by the system or on the system which will be positive or negative respectively.
Hence, 
dU= 250+80= 330 J
The change will be positive 
 
        
             
        
        
        
The answer i believe is A hope it helps
        
             
        
        
        
Answer:
a)  v² = G M R³,  b)  T = 2π / , c)
, c)  
Explanation:
a) The kinetic energy is
          K = ½ m v²
         
to find the velocity let's use Newton's second law
           F = m a
acceleration is centripetal
            a = v² / R
            
force is the universal force of attraction
            F = G m M / r²
we substitute
           G m M R² = m v² R
           v² = G M R³
            
the kinetic energy is
           K = ½ m G M R³
b) angular and linear velocity are related
           v = w R
           w = v / R
           w =  
           w =  
the angular velocity is related to the period
           w = 2π / T
           T = 2π / w
we substitute
            T = 2π / 
c) the angular moeomto is
             L = m v r
             L = m RA G M R³ R
             L =  