Answer:
2156J
Explanation:
Given parameters: 
Height of lift  = 10m 
Mass  = 22kg 
Unknown: 
Work done by the machine  = ? 
Solution: 
Work done is the force applied to move a body through a certain distance. 
So; 
         Work done  = Force x distance 
Here; 
        Work done  = mass x acceleration due to gravity x height 
       Work done  = 22 x 9.8 x 10  = 2156J
 
        
             
        
        
        
Answer:
F = 1263.03 N
Explanation:s
given,                      
mass of the disk thrower = 100 Kg
mass of the disk = 2 Kg                 
angular speed of the disk  = 4 rev/s
arm outstretched = 1 m                  
centripetal force of the disk in the circular path
F = m ω² r                        
ω = 4 x 2 x π        
ω = 25.13 rad/s
F = m ω² r                       
F = 2 x 25.13² x 1
F = 1263.03 N                                              
hence, centripetal force equal to the F = 1263.03 N
 
        
             
        
        
        
Answer:
Height, H = 25.04 meters
Explanation:
Initially the ball is at rest, u = 0
Time taken to fall to the ground, t = 2.261 s
Let H is the height from which the ball is released. It can be calculated using the second equation of motion as :

Here, a = g
 
             
 
 
H = 25.04 meters
So, the ball is released form a height of 25.04 meters. Hence, this is the required solution.
 
        
             
        
        
        
Refraction is a phenomenon which results when a ray of light enters from one medium to another medium. When a ray of light enters from denser medium to rarer medium, it bends away from the normal. The laws of refraction are: The incident ray, the refracted ray and the normal all lie in the same plane.