8. Thermochemistry

Kinetic & Potential Energy

Kinetic Energy

(d) What is the kinetic energy of an electron traveling at velocity (c)?

Kinetic & Potential Energy Example 1

What is the kinetic energy and velocity of the aluminum
sphere in Problem 1.4 at the moment it hits the ground? (Assume
that energy is conserved during the fall and that 100%
of the sphere’s initial potential energy is converted to kinetic
energy by the time impact occurs.)

 Systems with low potential energy tend to change in a direction of high potential energy by releasing energy into the surroundings. 

 To release energy, a system must change from a higher to a lower energy state.   This describes the opposite type of change from a lower energy state to a higher one. 

 Energy is seldom conserved in a physical or chemical change. 

 Potential energy cannot be destroyed; it can only be converted to thermal energy. 

 Potential energy can be converted to many forms of energy. 

 In any process, the total quantity of energy involved is constant. 

 Correct.  This is in accordance with the law of conservation of energy. 

 Energy is the action of a force operating through a certain distance. 

 Recall the law of conservation of energy. 

Which has more kinetic energy, a 1400-kg car moving at
115 km/h or a 12,000-kg truck moving at 38 km/h?

A radioactive particle weighing 7.20 x 103 ng is found 110 m above the earth’s surface. What is its potential energy?

 Potential energy decreases in this example. 

 Correct, due to because there is an electrostatic force of attraction between the electron and the nucleus. 

 The kinetic energy of the particles in the coffee and cup increase. 

 The potential energy of the spring decreases 

 Not all examples involve kinetic energy. 

 Kinetic energy is energy associated with the motion of an object; potential energy is energy associated with the position or composition of an object.   

 Which of the following results in a general increase in potential energy? 

For each of the following processes, does the potential
energy of the object(s) increase or decrease? 
(b) Water is pumped from ground level to the reservoir of a water tower 30 m above the ground.

Which has more kinetic energy, a 1400 kg car moving at 115 km/h or a 12,000 kg truck moving at 38 km/h?

"Our World: Potential and Kinetic Energy" by Adventure Academy

Kinetic Energy and Potential Energy

The accompanying photo shows a pipevine swallowtail caterpillar
climbing up a twig. (a) As the caterpillar climbs, its
potential energy is increasing. What source of energy has
been used to effect this change in potential energy?

 Kinetic energy is the energy of motion. 

 Correct.  Kinetic energy is directly related to velocity. 

 Kinetic energy is the energy relative to position. 

 Potential energy is related to position. 

 Kinetic energy is the energy available to do work. 

 All forms of energy can be used to do work. 

 Kinetic energy may be transformed into potential energy. 

 While this statement is correct, it does not define kinetic energy. 

 Kinetic energy is the energy associated with temperature. 

 Thermal energy is the form of energy associated with temperature. 

 Kinetic energy depends on mass and velocity. 

Which of the following best defines kinetic energy?

Consider the two spheres shown here, one made of silver and
the other of aluminum. (d) If you release the
spheres simultaneously, they will have the same velocity
when they hit the ground. Will they have the same kinetic
energy? If not, which sphere will have more kinetic energy?

Suppose an Olympic diver who weighs 52.0 kg executes a 
straight dive from a 10-m platform. At the apex of the dive, 
the diver is 10.8 m above the surface of the water. (b) Assuming that all the 
potential energy of the diver is converted into kinetic energy 
at the surface of the water, at what speed, in m>s, will the 
diver enter the water?

What’s the Difference between Potential and Kinetic Energy? | Science Max

Two positively charged particles are first brought close together
and then released. Once released, the repulsion between
particles causes them to move away from each other.
(b) Does the potential energy of
the two particles prior to release increase or decrease as the
distance between them is increased.

Classification of Matter

(a) Calculate the kinetic energy, in joules, of a 15-g bullet
moving at 120 m/s.

The kinetic energy of a gas molecule is connected to its mass in kilograms and velocity in meters per second.&nbsp;

Potential and kinetic energy - Law of conservation of energy - Video for kids

Kinetic & Potential Energy Example 2

Energy | Forms of Energy | Law of Conservation of Energy | Science Lesson for Kids

A 100-kg man decides to add to his exercise routine by walking
up six flights of stairs (30 m) 10 times per day. He figures that
the work required to increase his potential energy in this way
will permit him to eat an extra order of French fries, at 245 Cal,
without adding to his weight. Is he correct in this assumption?

The potential energy of a gas molecule is connected to its mass, acceleration due to gravity and height above the ground.&nbsp;

(b) Why does increasing the temperature cause a solid substance to change in suc- cession from a solid to a liquid to a gas?

What is the difference between heat and temperature? Between work and energy? Between kinetic energy and potential energy?

An electron with a mass of 9.1 * 10-28 g is traveling at 1.8 * 107 m/s in an electron microscope. Calculate the kinetic energy of electron in units of joules, and report your answer in scientific notation. (LO 1.11) 
(a) 1.5 * 10-16 J 
(b) 1.6 * 10-20 J 
(c) 2.9 * 10-13 J
(d) 2.9 * 10-10 J

The Difference Between Kinetic and Potential Energy

Suppose an Olympic diver who weighs 52.0 kg executes a
straight dive from a 10-m platform. At the apex of the dive,
the diver is 10.8 m above the surface of the water. (a) What
is the potential energy of the diver at the apex of the dive,
relative to the surface of the water?

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Professor Dave Explains

1. Intro to General Chemistry

2. Atoms & Elements

3. Chemical Reactions

4. BONUS: Lab Techniques and Procedures

5. BONUS: Mathematical Operations and Functions

6. Chemical Quantities & Aqueous Reactions

7. Gases

9. Quantum Mechanics

10. Periodic Properties of the Elements

11. Bonding & Molecular Structure

12. Molecular Shapes & Valence Bond Theory

13. Liquids, Solids & Intermolecular Forces

14. Solutions

15. Chemical Kinetics

16. Chemical Equilibrium

17. Acid and Base Equilibrium

18. Aqueous Equilibrium

19. Chemical Thermodynamics

20. Electrochemistry

21. Nuclear Chemistry

22. Organic Chemistry

23. Chemistry of the Nonmetals

24. Transition Metals and Coordination Compounds

[BOOK CHEM] Clutch Version

Hess's Law

Hess's Law involves the use of partial reactions in the determination of the overall enthalpy of reaction.

Nature of Energy

Thermochemistry is the study of matter and energy associated with chemical reactions or physical changes.&nbsp;

Endothermic & Exothermic Reactions

Endothermic and Exothermic Reactions involve the absorbing and releasing of thermal energy respectively.&nbsp;&nbsp;

Heat Capacity

Heat Capacity is the amount of heat required to change the temperature of a substance.&nbsp;

Thermochemical Equations

Thermochemical Equations&nbsp;involve a balanced chemical equation with a given enthalpy value.

Internal Energy

The Internal Energy of a system is the total energy from all forms of kinetic and potential energy.&nbsp;

Mechanical Energy is the energy associated with an object's velocity (Kinetic Energy) and its position (Potential Energy).&nbsp;

Formation Equations

Formation Equations involve the standard states of elements combining to form 1 mole of product.

Enthalpy of Formation

The Enthalpy of Formation for an element is a key component in determining the enthalpy of reaction.&nbsp;

Thermal Equilibrium

Thermal Equilibrium involves two substances that are in physical contact reaching the same final temperature over time.&nbsp;

Constant-Pressure Calorimetry

Constant-Pressure Calorimetry uses a coffee cup calorimeter to determine the heat transfers occurring in a liquid solution.

Constant-Volume Calorimetry

Constant-Volume Calorimetry uses a bomb calorimeter and a combustion reaction to determine its enthalpy of reaction.&nbsp;

First Law of Thermodynamics

The First Law of Thermodynamics states that energy cannot be created nor destroyed, but instead is transferred.&nbsp;