State and explain the law of conservation of mechanical energy with an example. [3 Marks]
1. Law of conservation of mechanical energy states that in the absence of friction, the sum of potential energy and kinetic energy remains constant at any instant. [1 Mark]
2. Let’s take an example. An object mass m is kept at the height h. Potential energy of the object is mgh and kinetic energy at that point is 0. Once it reaches to the ground floor, potential energy becomes zero and kinetic energy will be maximum. In between, the sum of potential and kinetic energy will be constant.
Potential energy + Kinetic energy = constant
[1 Mark]
3. If a body falls from a certain height, potential energy of the body reduces throughout the path and an equal amount of kinetic energy increases simultaneously.
mgh+mv22=constant;
This equation is followed throughout the path;
At the top most position, kinetic energy = 0 while at the bottom most position, potential energy = 0. [1 Mark]
1. Law of conservation of mechanical energy states that in the absence of friction, the sum of potential energy and kinetic energy remains constant at any instant. [1 Mark]
2. Let’s take an example. An object mass m is kept at the height h. Potential energy of the object is mgh and kinetic energy at that point is 0. Once it reaches to the ground floor, potential energy becomes zero and kinetic energy will be maximum. In between, the sum of potential and kinetic energy will be constant.
Potential energy + Kinetic energy = constant
[1 Mark]
3. If a body falls from a certain height, potential energy of the body reduces throughout the path and an equal amount of kinetic energy increases simultaneously.
mgh+mv22=constant;
This equation is followed throughout the path;
At the top most position, kinetic energy = 0 while at the bottom most position, potential energy = 0. [1 Mark]
