Answer:
a) t = 1.6 s
b) d = 4.9 m
c) v = 16 m/s
d) θ = 79°
Explanation:
time of fall 
t = √(2h/g) = √(2(12)/9.8) = 1.5649... s 
d = vt = 3.1(1.56) = 4.8512...
vertical velocity vy = at = 9.8(1.56) = 15.336... m/s
v = √(15.336² + 3.1²) = 15.6464... m/s
θ = arctan(15.336/3.1) = 78.5724...°
 
        
             
        
        
        
1 gram per cubic centimeter is equal to 1000 kilograms per cubic meter. Just multiply it with a 1000 and you have your solution.
        
             
        
        
        
Potential energy and kinetic energy.
Hope this helps
        
                    
             
        
        
        
Howdy!!
your answer is ----
total resistance 1/R = 1/9+1/9+1/9
 = 3/9
=> R = 9/3 = 3 ohm
according to ohms law 
voltage = current × resistance
 = 4 × 3 = 12 volt
hope it help you
        
             
        
        
        
It's i<span>onic Compunds hope it helps!</span>