Give reasons for the following : (a) No work is done if a man is pushi

1.	Give reasons for the following : (a) No work is done if a man is pushing against a wall. (b) The hammer drives a nail into the wood only when it is lifted up and then struck. (c) A horse and a dog are running at the same speed. Which one of them has more kinetic energy than the other (d) A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work?
Answer» Give reasons for the following : (a) No work is done if a man is pushing against a wall. (b) The hammer drives a nail into the wood only when it is lifted up and then struck. (c) A horse and a dog are running at the same speed. Which one of them has more kinetic energy than the other (d) A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work?

Give reasons for the following : (a) No work is done if a man is pushing against a wall. (b) The hammer drives a nail into the wood only when it is lifted up and then struck. (c) A horse and a dog are running at the same speed. Which one of them has more kinetic energy than the other (d) A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work?

Answer»

Give reasons for the following :

(a) No work is done if a man is pushing against a wall.

(b) The hammer drives a nail into the wood only when it is lifted up and then struck.

(d) A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work?