Which of the Following is an Expression of the Kinetic Energy?
Question:
Which of the following is an expression of the kinetic energy?
- A) mgh
- B) ½ mv²
- C) ½ kx²
- D) F × d
Answer:
The correct expression for the kinetic energy of an object is:
KE = ½ mv²
Where:
- m = mass of the object (in kilograms)
- v = velocity of the object (in meters per second)
✅ Therefore, the correct answer is: Option B) ½ mv²
Explanation of Other Options:
- Option A (mgh): This is the formula for gravitational potential energy, not kinetic energy.
- Option C (½ kx²): This is the formula for elastic potential energy stored in a spring.
- Option D (F × d): This represents work done by a force when the force is constant and acts in the direction of displacement.
Conclusion:
Kinetic energy is the energy of motion and is correctly expressed by the equation:
KE = ½ mv²
This distinguishes it clearly from potential energy and work.