Because water is a very very very very very unusual substance ... It's
the only known substance whose solid form is less dense than its liquid
form near the same temperature.
In other words, water is the only known substance for which a solid lump
of it floats in a liquid glass of it.
If that were not true ... if the behavior of the density of water around its
freezing temperature were the same as the density of all other known
substances ... then life on Earth would be impossible.
Think about that for a while ! Ya gotta admire whoever it was that designed water !
Answer:
Work done, W = -318.19 Joules
Explanation:
It is given that,
Force acting on the object, F = 50 N
Distance covered by the force, d = 9 m
Angle between the force and the distance traveled, 
The work done by an object is equal to the product of force and distance traveled. It is equal to the dot product of force and the distance. Mathematically, it is given by :


W = -318.19 Joules
So, the work done by the force is 318.19 Joules. The work is done in opposite to the direction of motion. Hence, this is the required solution.
Changing magnetic fields induce electric currents in copper and other conductors.