Question

21 A body of mass 10 kg is initially at a height of 20 m above the ground its it falls to a heig 5 m above the ground its potential energy in the new position is a) 4903 b) 50J c) 100J d) 300J​

Answer 1

Answer:

1500 J]

Formula,

k=  

2

1

​

mv  

2

 

work done by air resistance,

=k  

2

​

−k  

1

​

 

=  

2

1

​

mv  

2

2

​

−  

2

1

​

mv  

1

2

​

 

=  

2

1

​

×10×(2×10×20)−  

2

1

​

×10×(10×10)

=2000−500=1500J

Explanation: