Mechanical Energy

What is Mechanical Energy?

• Mechanical Energy is the sum of potential energy and kinetic energy in a system.

• Mechanical Energy is the energy stored in an object due to its position.

• Mechanical Energy is the energy associated with the motion of an object only.

• Mechanical Energy is the energy that can be converted into heat.

What is the principle of conservation of mechanical energy?

• The principle states that in a closed system, the total mechanical energy (GPE + KE) remains constant if only conservative forces are acting.

• The principle states that energy can be created and destroyed in a closed system.

• The principle states that mechanical energy is always converted into thermal energy in a closed system.

• The principle states that the total energy in a closed system is always increasing.

How does mass affect GPE?

• GPE is inversely proportional to mass; if mass increases, GPE decreases.

• GPE is directly proportional to mass; if mass increases, GPE increases.

• Mass has no effect on GPE; it remains constant regardless of mass.

• GPE is proportional to the square of mass; if mass increases, GPE increases exponentially.

What is the unit of energy in the International System of Units (SI)?

• Calorie (cal)

• Joule (J)

• Watt (W)

• Electronvolt (eV)

Define Gravitational Potential Energy (GPE).

• Gravitational Potential Energy (GPE) is the energy an object possesses due to its position in a gravitational field, calculated as GPE = mgh (mass x gravity x height).

• Gravitational Potential Energy (GPE) is the energy an object has due to its speed and direction of motion.

• Gravitational Potential Energy (GPE) is the energy stored in an object due to its temperature and thermal state.

• Gravitational Potential Energy (GPE) is the energy an object possesses due to its mass and the force of friction acting on it.

At what point is GPE maximum in a free-falling object?

• At the highest point of the object's path.

• At the lowest point of the object's path.

• Halfway down the object's path.

• When the object is in motion.

What is the relationship between GPE and height?

• GPE decreases as height increases, assuming mass and gravity remain constant.

• GPE remains constant regardless of height changes.

• GPE increases as height increases, assuming mass and gravity remain constant.

• GPE is independent of height and depends only on mass.

What happens to the total mechanical energy in the absence of non-conservative forces?

• The total mechanical energy increases due to external work.

• The total mechanical energy decreases over time.

• The total mechanical energy remains constant in the absence of non-conservative forces like friction.

• The total mechanical energy becomes zero.

What is an example of a situation where GPE is converted to KE?

• A roller coaster descending from a height converts GPE into KE as it speeds up.

• A car accelerating on a flat road converts KE into GPE.

• A ball thrown upwards converts KE into GPE as it rises.

• A pendulum swinging back and forth converts GPE into thermal energy.

How do you calculate the total mechanical energy of a system?

• Total Mechanical Energy = Gravitational Potential Energy + Kinetic Energy.

• Total Mechanical Energy = Gravitational Potential Energy - Kinetic Energy.

• Total Mechanical Energy = Kinetic Energy - Potential Energy.

• Total Mechanical Energy = Gravitational Potential Energy * Kinetic Energy.