HEAT AND WORK (THERMODYNAMIC
AND HEAT TRANSFER) EXAM
QUESTIONS WITH COMPLETE
SOLUTIONS
- It should also be noted that work and heat are closely related. - ANSWER-Both can
change the temperature of a substance, and heat can be turned into work (not perfectly)
and work can be turned into heat. This equivalence is the basis of how heat engines
power modern society.
- Work - ANSWER-is the transfer of mechanical energy from one object to another.
Since work is a movement of energy, it is measured in the same units as energy: joules
(J).
- The definition of work in a physics context is quite different from how it is used in a
person's daily life and is as follows - ANSWER-:" Work is done when a force is applied
to an object through a distance."
- This means that when a force is applied to an object through a distance, the object's
total energy will be affected. - ANSWER-The object will either speed up or slow down,
resulting in a change in its kinetic energy, or it will have an altered potential energy if, for
example, it was lifted a certain height under the force of gravity.
- Work also extends beyond what a person can physically see. - ANSWER-It can also
affect the microscopic properties of a system, such as temperature.
- In 1843 this idea began to be explored by scientists, and its results led to the
formulation of what is now known as thermodynamics. - ANSWER-Doing work on a
system can affect its internal energy, just like adding heat can. However, the two
processes are fundamentally different.
- All of the cases described so far of how work can affect a system can be summed up
in a single equation:
W=ΔK+ΔU+ΔEth - ANSWER-- This equation says that work (W) can change (Δ) a
system's kinetic energy (K), potential energy (U), thermal energy (Eth), or any
combination of the three.
The actual work done can be calculated using the following formula:
W= F ⇢ • D⇢ - ANSWER-W is work, or a change in mechanical energy, measured in
joules (J)
F is force measured in newtons (N)
d is displacement of the object
AND HEAT TRANSFER) EXAM
QUESTIONS WITH COMPLETE
SOLUTIONS
- It should also be noted that work and heat are closely related. - ANSWER-Both can
change the temperature of a substance, and heat can be turned into work (not perfectly)
and work can be turned into heat. This equivalence is the basis of how heat engines
power modern society.
- Work - ANSWER-is the transfer of mechanical energy from one object to another.
Since work is a movement of energy, it is measured in the same units as energy: joules
(J).
- The definition of work in a physics context is quite different from how it is used in a
person's daily life and is as follows - ANSWER-:" Work is done when a force is applied
to an object through a distance."
- This means that when a force is applied to an object through a distance, the object's
total energy will be affected. - ANSWER-The object will either speed up or slow down,
resulting in a change in its kinetic energy, or it will have an altered potential energy if, for
example, it was lifted a certain height under the force of gravity.
- Work also extends beyond what a person can physically see. - ANSWER-It can also
affect the microscopic properties of a system, such as temperature.
- In 1843 this idea began to be explored by scientists, and its results led to the
formulation of what is now known as thermodynamics. - ANSWER-Doing work on a
system can affect its internal energy, just like adding heat can. However, the two
processes are fundamentally different.
- All of the cases described so far of how work can affect a system can be summed up
in a single equation:
W=ΔK+ΔU+ΔEth - ANSWER-- This equation says that work (W) can change (Δ) a
system's kinetic energy (K), potential energy (U), thermal energy (Eth), or any
combination of the three.
The actual work done can be calculated using the following formula:
W= F ⇢ • D⇢ - ANSWER-W is work, or a change in mechanical energy, measured in
joules (J)
F is force measured in newtons (N)
d is displacement of the object
