Question

1. Work is said to be done
2. If a force causes zero displacement, then work done is
3. Complex machines are made of a combinatis, of
combinatis, of two or more​

Answer 1

Answer:

1 joule of work is said to be done when a force of 1 Newton moves an object through a distance of 1 meter in direction of force.

2) Explanation: Work in Physics is said to be done when the objects gets displaced from its initial position when force is applied on it or their in increase in the object's kinetic energy. If displacement = 0, then velocity and hence kinetic energy = 0 and hence no work is done.

3) Also called simple machine. any of six or more elementary mechanisms, as the lever, wheel and axle, pulley, screw, wedge, and inclined plane. Also called complex machine. a combination of simple machines.