Work= (force)(distance)
178= m(9.81)x0.5
178=m(4.905) 
178/4.905=m
His mass is 36.3 kg
        
                    
             
        
        
        
Answer:

Explanation:
Given data:



Let the distance traveled by the object in the second case be 
In the given problem, work done by the forces are same in both the cases.
Thus,





 
        
             
        
        
        
If the vertical component is 29.6 m/s down, and the horizontal component 
is 54.8 m/s parallel to the surface, then the magnitude of the slanty vector is
   √(29.6² + 54.8²) = √(876.16 + 3003.04) = √3879.2  =  62.28 m/s . 
That's 139 mph !  Wow !
        
             
        
        
        
Answer:
option (C) 
Explanation:
The amount of heat required to raise the temperature of substance of unit mass by unit degree is called specific heat of that substance. 
Its SI unit is Joule / Kg °C. 
Every material has a constant value of specific heat.
So, option (c) is correct.