Explanation: Mass is Kilogram
 Weight is Newton
 
        
             
        
        
        
Answer: final Velocity v = 10.2m/s
Explanation:
Final speed v(t) is given as
v(t) = u + at .......1
Where; u = the initial speed
a = acceleration 
t = time taken
The total distance travelled d is given as
d = ut + 1/2(at^2)
 
Given 
d = 5.0m
u = 2.0m
a = g = 10m/s2 (acceleration due to gravity)
 
Substituting into the equation above we have
5 = 2t + 5t^2
5t^2 +2t -5 = 0
Applying the quadratic formula. We have;
t = 0.82s & t = -1.22s
t cannot be negative
t = 0.82s
From equation 1 above
v = 2.0m/s + 10(0.82)m/s
v = 10.2m/s
 
        
                    
             
        
        
        
The expression for the magnitude of the electric field between two uniform conducting plates is

Here, V is potential difference between plates and d is separation between plates.
As the potential 6.00 cm from the zero volt plate (and 4.00 cm from the other) is 420 V.
Therefore,

Thus, the electric field strength between the plates is 7000 V/ m
 
 
        
             
        
        
        
Answer:
8 signals received by twin A during the trip.
Explanation:
Given that,
Distance = 12 light year 
Speed = 0.6 c
Time = 1 year
We need to calculate the time by A
Using formula of time

Put the value into the formula


Similarly,
The expression for distance cover by A



We need to calculate the time
Using formula of time



We need to calculate the signals received by twin A
Using formula for number of signals

Put the value into the formula


Hence, 8 signals received by twin A during the trip.