Given that,
Mass of the stone, m = 400 g = 0.4 kg
Initial speed, u = 20 m/s
It is climbed to a height of 12 m.
To find,
The work done by the resistance force.
Solution,
Let v is the final speed. It can be calculated by using the conservation of energy.

Work done is equal to the change in kinetic energy. It can be given as follows :

So, the required work done is 32.99 J.
Look that one up in you text book PG:678 that is if you got the same book as my friend<span />
By definition we know that the force is the vector product of the vector of the current by the length with the magnetic field vector. The current in this case goes in a positive "Y" direction. If we assume that the magnetic field goes in the positive "K" direction, then the result will be in the positive "X" direction. Attached solution.
Answer:
The force exerted by three charges on the fourth is 
Explanation:
Given:
- The magnitude of three identical charges,

- Length of the edge of the square a=3 cm
- Magnitude of fourth charge ,Q=3 nC
According to coulombs Law the force F between any two charge particles is given by

where r is the radial distance between them.
Since the force acting on the charge particle will be in different directions so according to triangle law of vector addition
