The document discusses several concepts related to energy and motion: 1. It defines the Law of Conservation of Energy as stating that the total energy of an isolated system cannot change over time, and that energy can change form but not be created or destroyed. 2. It explains that the First Law of Thermodynamics is a version of the Conservation of Energy law adapted for thermodynamic systems, recognizing the internal energy of a body. 3. It differentiates exothermic reactions, where heat is released, from endothermic reactions, where heat is absorbed.

1. Kesha Mae Sagaoinit
III-SSC
1. State the Law of Conservation of Energy
The law of conservation of energy states that the total energy of an isolated system cannot
change—it is said to be conserved over time. Energy can be neither created nor destroyed, but
can change form, for instance chemical energy can be converted to kinetic energy in the
explosion of a stick of dynamite.
2. State the First Law of Thermodynamics
The first law of thermodynamics is a version of the law of conservation of energy, adapted
for thermodynamic systems. The law of conservation of energy states that the total energy of an
isolated system is constant; energy can be transformed from one form to another, but cannot be
created or destroyed. The first law of thermodynamics recognizes a particular component of a
body's total energy called internal energy. The internal energy of a body is distinguishable from
the kinetic energy of motion of the body as a whole, and from the potential energy of position of
the body as a whole in an external force field. The total energy of the body is the sum of its
internal, bulk kinetic, and bulk potential energies.
The law is often formulated by stating that the change in the internal energy of a closed
system is equal to the amount of heat supplied to the system, minus the amount of work derived
from the system. It is also often formulated by stating that when a closed system has a change
of state, and its internal energy is changed only by work and not by heat transfer, then the net
amount of work transferred is the same for all arrangements of work transfer that can possibly
produce that change of state. Also, when two systems, open to each other for transfer of matter
and energy, interact but are otherwise isolated, then the sum of their internal energies does not
change; this recognizes that, in general, with transfer of matter between systems, there is also
transfer of internal energy; such transfer of energy is neither heat nor work.
3. Differentiate Exothermic from Endothermic Reactions
In an exothermic chemical reaction, energy or heat is released. As an exothermic reaction
occurs, its energy is released into its surrounding environment. The products of an exothermic
reaction have less heat than the reactants. The majority of reactions that occur in everyday
situations are exothermic in nature. While in an endothermic chemical reaction, energy or heat
is absorbed. Over the course of an endothermic reaction, the reacting system takes energy from
its surroundings to produce a reaction. The products of an endothermic reaction have more heat
than the reactants.
4. Differentiate following quantities:
a. Scalar and Vector
You can differentiate scalar quantity and vector quantity by: (1) the scalar quantity only
comprises of magnitude whereas a vector quantity consists of both magnitude and direction.
(2)Mass and Volume are the examples of scalar quantity while Force, Acceleration, Velocity
are examples of vector quantity. (3) The usual laws of algebra are applicable to scalar
quantities. They are not applicable for vector quantities. (4) The symbol for a vector normally

2. will be a boldfaced letter with an arrow overhead. (5) The square of a scalar is positive and
the square of a vector is negative.
b. Distance and Displacement
Distance and Displacement are differentiated in that distance is the scalar quantity
representing the interval between two points while displacement is a vector value of how
far an object has been displaced meaning how far it is from where it started.
c. Speed and Velocity
The difference between speed and velocity is that speed is a scalar quantity while
velocity is a vector quantity. Velocity takes into account the magnitude of a moving object
measured in a specific direction while speed is the measure of magnitude or strength of
a moving object.
d. Average Speed and Instantaneous Speed
Average speed is the distance traveled divided by the amount of time taken to make the
journey while instantaneous speed is the rate of change of position of an object with
respect to time and at a particular point.

3. Edwina De Guzman
III-SSC
1. State the Law of Conservation of Energy
The law of conservation of energy states that the total energy of an isolated system cannot
change—it is said to be conserved over time. Energy can be neither created nor destroyed, but
can change form, for instance chemical energy can be converted to kinetic energy in the
explosion of a stick of dynamite.
2. State the First Law of Thermodynamics
The first law of thermodynamics is a version of the law of conservation of energy, adapted
for thermodynamic systems. The law of conservation of energy states that the total energy of an
isolated system is constant; energy can be transformed from one form to another, but cannot be
created or destroyed. The first law of thermodynamics recognizes a particular component of a
body's total energy called internal energy. The internal energy of a body is distinguishable from
the kinetic energy of motion of the body as a whole, and from the potential energy of position of
the body as a whole in an external force field. The total energy of the body is the sum of its
internal, bulk kinetic, and bulk potential energies.
The law is often formulated by stating that the change in the internal energy of a closed
system is equal to the amount of heat supplied to the system, minus the amount of work derived
from the system. It is also often formulated by stating that when a closed system has a change
of state, and its internal energy is changed only by work and not by heat transfer, then the net
amount of work transferred is the same for all arrangements of work transfer that can possibly
produce that change of state. Also, when two systems, open to each other for transfer of matter
and energy, interact but are otherwise isolated, then the sum of their internal energies does not
change; this recognizes that, in general, with transfer of matter between systems, there is also
transfer of internal energy; such transfer of energy is neither heat nor work.
3. Differentiate Exothermic from Endothermic Reactions
In an exothermic reaction, heat is produced as one of the end products. An example of this is
when a candle burns. An endothermic reaction is one in which heat is absorbed--heat is needed
to finish the reaction.
4. Differentiate following quantities:
a. Scalar and Vector
Scalars are quantities that have magnitude only; they are independent of direction. Vectors
have both magnitude and direction. The length of a vector represents magnitude. The arrow
shows direction.
b. Distance and Displacement
The difference between distance and displacement comes down to dimensions. Basically
a distance is a measurement of the space between two points. Displacement is the
volume of space that something takes up. The volume taken up is pushed out of the way,
like a boat pushing the water out of the way when it is in the water.

4. c. Speed and Velocity
The difference between speed and velocity is that speed is a scalar quantity while
velocity is a vector quantity. Velocity takes into account the magnitude of a moving object
measured in a specific direction while speed is the measure of magnitude or strength of
a moving object.
d. Average Speed and Instantaneous Speed
Average speed is the distance traveled divided by the amount of time taken to make the
journey while instantaneous speedis the rate of motion of something at a specific
moment in time.