Answer:
the rate of acceleration of the train is 4 m/s²
Explanation:
Given;
initial velocity of the train, u = 10 m/s
change in time of motion, dt = 5 s
final velocity of the train, v = 30 m/s
The rate of acceleration of the train is calculated as;

Therefore, the rate of acceleration of the train is 4 m/s²
 
        
             
        
        
        
Answer:
2.5 ohm
Explanation:
R' and R''' are parallel
So,
1/R1= 1/R' + 1/R'''
1/R1 = 1/2 + 1/2
1/R1 = 1
so,
R1= 1 ohm
Now R1 and R'' are in series
so,
R= R1 + R''
R= 1 + 1.5
R= 2.5 ohm
 
        
             
        
        
        
D. all of these
all of these use electricity
Hope I helped! 
        
                    
             
        
        
        
The kinetic energy is the same as the potential energy of raising it 40cm (0.4m). That's mgh where m is mass of ball. Its then 3.924*m, whatever m is equal to in kg.
        
             
        
        
        
 The force of gravity between Earth and Mars will decrease.
The gravitational law is given as-
            F = G mM/r²
   here,  m= mass of rocket
              M = mass of earth
              r = distance between earth and rocket
 So, as rocket takes off from earth and fly towards mars then the distance starts to increase between earth and rocket, and the gravitational pull between them starts to weaken. Then a point will reach when rocket will far from gravity of earth and could probably enter the gravity of Mars. 
Learn more about gravitational law here:
  brainly.com/question/12101547
      #SPJ4