Answer:
a.) The main scale reading is 10.2cm
b.) Division 7 = 0.07
c.) 10.27 cm
d.)  10.31 cm
e.)  10.24 cm  
Explanation:
The figure depicts a vernier caliper readings
a.) The main scale reading is 10.2 cm
The reading before the vernier scale
b.) Division 7 = 0.07
the point where the main scale and vernier scale meet
c.) The observed readings is
10.2 + 0.07 = 10.27 cm
d.) If the instrument has a positive zero error of 4 division
correct reading = 10.27 + 0.04 = 10.31cm
e.)  If the instrument has a negative zero error of 3 division
correct reading = 10.27 - 0.03 = 10.24cm  
 
        
             
        
        
        
5m
Explanation:
Given parameters: 
Weight of object = 50N 
Work done in lifting object = 250J 
Unknown:
Vertical height = ? 
Solution: 
The work done on an object is the force applied to lift a body in a specific direction. 
    Work done = force x distance
   Weight is a force in the presence of gravity; 
   Work done = weight x height of lifting 
Height of lifting = 
  Height of lifting =  = 5m
 = 5m
The vertical height through which the object was lifted is 5m
learn more: 
Work done brainly.com/question/9100769
#learnwithBrainly
 
        
             
        
        
        
Answer is B. According to the equation of motion s = vt + 1/2 at2 Where s is distance covered, v is velocity, a is acceleration and t is time taken. So, by putting all the values, we get s = (20)(5) + 1/2 (3)(5)2 s = 100 + 1/2 (3)(25) s = 100 + 1/2 75 s = 100 + 37.5 s = 137.5 meters 
 
        
                    
             
        
        
        
Batteries Produce DC current while homes produce AC current.
Hope this helped xxxx