Answer:
The final  velocity of the cart is   
 
Explanation:
From the question we are told that 
     The mass of the girl is  
      The mass of the cart is  
       The speed of the cart and  kid(girl) is  
      The final velocity of  the girl is 
Let assume that velocity eastward is  positive and velocity westward is negative (Note that if we assume vise versa it wouldn't affect the answer )
    The total momentum of the system before she steps off the back of the cart
is mathematically evaluated as 
         
substituting values 
         
         
The total momentum after she steps off the back of the cart is mathematically evaluated as 
         
Where   is the final velocity of the cart
  is the final velocity of the cart 
substituting values     
       
        
Now according to the law of conservation of momentum 
        
So  
        
=>      
Since the value is positive it implies that the cart moved eastward 
 
        
             
        
        
        
Answer:
Explanation:
α = (ωf - ωi)/t
acceleration phase 
ωf = 132 rev/min (2π rad/rev / 60 s/min) = 4.4π rad/s
α₁ = (4.4π - 0)/20 = 0.22π rad/s²
α₂ = (0 - 4.4π)/40 = - 0.11π rad/s²
α₁/α₂ = 0.22π/- 0.11π = -2
 
        
             
        
        
        
<h3><u>Question</u><u>:</u></h3>
A racing car is travelling at 70 m/s and accelerates at -14 m/s^2. What would the car’s speed be after 3 s?
<h3><u>Statement:</u></h3>
A racing car is travelling at 70 m/s and accelerates at -14 m/s^2.
<h3><u>Solution</u><u>:</u></h3>
- Initial velocity (u) = 70 m/s
- Acceleration (a) = -14 m/s^2
- Time (t) = 3 s
- Let the velocity of the car after 3 s be v m/s
- By using the formula,
 v = u + at, we have

- So, the velocity of the car after 3 s is 28 m/s.
<h3><u>Answer:</u></h3>
The car's speed after 3 s is 28 m/s.
Hope it helps
 
        
        
        
You divide 120 and 72 and get 1.67 repeated i think
        
             
        
        
        
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 =  