Question

Select the true statements about mechanical work and energy.

a. In theory, energy is conserved through the system and transitions from one energy type to another; in reality, some energy is often lost as it transitions to heat, light, sound, etc.
b. Finding the rotational work in Joules involves taking the dot product between a net joint moment in Nm and an joint's angular displacement in degrees
c. Scenarios can exist where mechanical work completed can be a nonzero number, but the external work in the system is zero.

Answer 1

Select statements about mechanical work and energy include that energy theoretically is conserved but can be lost as heat or sound, rotation work is calculated using radians, and mechanical work can be non-zero with zero external work in a system.

Step-by-step explanation:

When discussing mechanical work and energy, it's important to consider the following true statements:

• In theory, energy is conserved through the system and transitions from one energy type to another; in reality, some energy is often lost as it transitions to heat, light, sound, etc.
• Finding the rotational work in Joules involves taking the dot product between a net joint moment in Nm and a joint's angular displacement in radians, not degrees.
• Scenarios can exist where mechanical work completed can be a nonzero number, but the external work in the system is zero.

Conservation of energy is a fundamental principle in physics, stating that the total energy of a system remains constant if there is no net addition or subtraction of work or heat transfer. Mechanical energy, which is the sum of kinetic and potential energy, can be transferred into or out of a system when a force causes displacement.