B verifying is the answer
        
             
        
        
        
Acceleration is a derived unit because it is derived from two quantities : Velocity and time.
We know, acceleration = Change in velocity/Time
 
        
                    
             
        
        
        
Answer:
 8.3m/s
Explanation:
Given parameters: 
mass of clay ball  = 5kg 
Speed of clay ball  = 25m/s 
mass of clay ball at rest  = 10kg 
speed of clay ball at rest  = 0m/s 
Unknown: 
Velocity after collision  = ? 
Solution: 
  Since the balls stick together, this is an inelastic collision: 
    m1v1 + m2v2  = v(m1 + m2)
   5(25) + 10(0)  =  v (5 + 10)
          125 = 15v 
            v  = 8.3m/s
 
        
             
        
        
        
Answer:
In D: 3J
Explanation:
Potential energy: Ep=mgh where m is the mass, h altitude.
In point A: h=20cm=0.2m
Epa=12=0.2×mg. Thus mg=12/0.2=60N
For point D: hd=5cm=0.05m
Epd=mg×0.05=60×0.05=3J