Physics
A spring is compressed storing potential energy. When the spring is released it propels an object forward. What change would you notice in the total mechanical energy of the system?
- It increases
- It decreases
- It becomes zero
- It remains constant
Answer
It remains constant
Reason — When the spring is compressed, it stores potential energy. Upon release, this potential energy is converted into kinetic energy as the spring propels an object forward. Assuming there are no significant external forces acting on the system (such as friction), the total mechanical energy of the system remains constant.
Related Questions
According to the principle of conservation of mechanical energy :
- Potential energy of a system is always greater than its kinetic energy
- Kinetic energy of a system is always greater than its potential energy
- Mechanical energy is always converted into heat energy
- Total mechanical energy of a system remains constant if no external force is worked on it.
A skater is gliding on a smooth ice surface. What happens to his mechanical energy as he skates?
- It increases
- It decreases
- It becomes zero
- It remains constant
When a car is moving on a level road and breaks are applied till it comes to rest, what happens to its mechanical energy?
- It increases
- It decreases
- It becomes zero
- It becomes negative
A ball of mass m is thrown vertically up with an initial velocity so as to reach a height h. The correct statement is:
- Potential energy of the ball at the ground is mgh.
- Kinetic energy of the ball at the ground is zero.
- Kinetic energy of the ball at the highest point is mgh.
- Potential energy of the ball at the highest point is mgh.