physics class 6 work and energy

The SI unit of work or energy is joule. Explain why the work and energy have same SI unit.

In Physics, work is not done when you push a wall.

With the help of a diagram, explain the physical significance of energy of activation (E_(a)) in chemical reactions.

In Physics, reading a book and pushing a wall are considered to be work.

Photoelectric emission from a given surface of metal can take place when the value of a ‘physical quantity’ is less than the energy of incident photon. The physical quantity is :

Write the negation of each of the following statements. Shekhar is in class 6 or Poonam is in class 7.

Explain the change of heat energy in a physical change.

Assertion :- According work energy theorem net work done on a body is equal to change in its kinetic energy. Reason :- The work energy theorem is independent of Newton's second law.