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.
Answer:
If the two forces applied to an object act in the same direction ,then the resultant force acting on the object is equal to the sum of two forces: When two forces act in the same direction their effective magnitude increases
Explanation:
Answer:
in this ionic compound, oxygen has 2 excess electrons and magnesium has two electrons missing.
Explanation:
When oxygen is mixed in a chemical reaction, it acquires two electrons from magnesium, to become an ion with 2 negative .
Mg + O → MgO
Therefore, in this ionic compound, oxygen has 2 excess electrons and magnesium has two electrons missing