Energy Concepts
What is the energy of a baby who weighs 20N sitting in a high chair 1.5m high?
1.36J
A force of 85 N is used to push a box along the floor a distance of 15m. How much work is done?
1275kg
What is the kinetic energy of a bike with a mass of 16 kg traveling at 4m/s?
128J
A go-cart and rider have a mass of 100 kg. If the cart accelerates at 5 m/s2 during a 25m sprint, how much work did the cart do?
2500 kg
how much power is used if a force of 90 N is used to push a box a distance of 30m in 10s
270 W
A 10 kg rock falls from a height of 18 m and lands on a guy about 3 s later. How much power did it hit him with?
60 W
How much heat is needed warm 0.072 kg of gold from 20 C to 90 C if the specific heat of gold is 136 J/kg/C
685.44 J
How high is a 0.5 kg squirrel sitting if it has 36 J of energy?
7.35m
150J of work was done to lift a crate with a force of 20 N. How far was the crate lifted?
7.5 m
What is the energy of a 4kg apple that is sitting on a 2m high tree branch?
78.4 J
What is the relationship between kinetic and potential energy of a falling object.
As the object falls its potential energy decreases and its kinetic energy increases.
Explain the difference between the 3 types of thermal energy transfer. Include an example of each.
Conduction- transfer of energy through matter by direct contact of particles. Ex. heat from a hot pot transferring to the metal ladle sitting in the pot. Convection- Transfer of energy by the movement of heated particles. Ex. Boiling water Radiation- Transfer of energy through electromagnetic waves. Ex. Fire flame heating up a tin can
List examples of materials that would classify as conductors vs. insulators.
Conductors: Copper, Aluminum, and Gold Insulators: Rubber, Styrofoam, and Paper
Describe how thermal energy flows when a person is sitting in a chair at their desk
The thermal energy goes from a high temperature object to the object that has a lower temperature.
kinetic energy
the energy an object has due to its motion
Specific Heat
the heat required to raise the temperature of one gram of a substance one degree centigrade
Power
the rate at which work is done
Mechanical Energy
the total amount of potential and kinetic energy in a system
potential energy
stored energy
Explain the differences between the 3 types of potential energy
Elastic Potential Energy- Energy stored in objects being compressed or stretched Chemical Potential Energy- Energy stored in chemical bonds of compounds Gravitational Potential Energy- Energy stored in objects that are above Earth's surface
Electromagnetic Energy
Form of energy that is reflected or emitted in the form of electrical and magnetic waves that can travel through space.
Conducter
A material that allows heat and electricity to pass through it.
Insulator
A material that does not allow heat or electrons to move through it easily.
Temperature
A measure of the average kinetic energy of the particles in a substance
gravitational potential energy
Energy stored by objects due to their position above Earth's surface.
Explain why there is no such thing as cold.
Everything has heat, it is just has a lower amount of heat and that makes things feel cold.
Thermal Energy
Heat that comes from a fire and sun. Used to heat objects.
Explain the relationship between temperature and kinetic energy.
If there is a high amount of kinetic energy, the temperature will be high too.
Determine the energy of conversion for the following: a. Light Bulb b. Firework c. Flute d. Leaf
Light bulb= Electrical --> Light Firework= Chemical --> light/thermal/sound Flute= Kinetic --> Sound Leaf= Radiant -->Chemical
Give an example of where you would find each of the following types of energy; radiant, thermal, sound, nuclear, and electromagnetic.
Radiant= Light bulbs, Thermal= Fire, Sound= Fireworks, Nuclear= Sun, Electromagnetic= Phone
Energy
The ability to cause change
Draw a picture of a pendulum or someone hitting a golf ball, showing how GPE, KE, and ME change throughout the object's motion.
The ball has a low GPE when it is on the ground. It has a high KE when the ball is hit. When the ball is in the middle of the air it has a high GPE and a low KE. Then when the ball has landed on the ground it has a low GPE and a high KE.
Heat
The energy transferred between objects that are at different temperatures
Law if Conservation of Energy
The study of the various forms of energy and the transformations from one form into another
Work
Transfer of energy that occurs when a force makes an object move
