What is needed to do daily work?

What is understood by no-work force ?

Four charges are arranged at the comers of a square ABCD of side d as shown in Fig. A charge q_0 is brought to the centre E of the square, the four charges being held fixed at its corner. How much extra work is needed to do this ?

What is the need of calorie in our body?

Why is it necessary to do work to increase the length of a wire by stretching it? Which form is this work converted into?

The enthalpy change involved in the oxidation of glucose is -2880 kJ mol^-1 . Twenty five percent of this energy is available for muscular work. If 100 kJ of muscular work is needed to walk one kilomtere, what is the maximum distance that a person will be able to walk after eating 120 g of glucose?

The amount of usable energy that is available for doing work in a system is

My friend Rina can do garden work alone in 4 hours. I can do that work alone in 3 hours. But if we together do that work, let’s calculate how much time will be needed.

What should be the angle between force and displacement vector for a force to do maximum work ?

A force is acting on a body in motion, but is not doing any work. Give an example of such a force.