Name______Date______Physical Science

Chapter 15: Energy

Section 15.1: Energy and Its Forms

  • ______is the ability to do ______or supply ______.
  • When ______is done on an object, the ______is ______to that object.
  • Both ______and ______are measured in ______.
  • Many forms of ______can be classified into two general types: ______.
  • ______is the energy of ______.
  • Formula for kinetic energy

KE =

m =

v =

  • Notice that ______the ______would ______the ______.
  • However, ______the ______would ______the ______.

KE = ½ mv2

½ (50kg)(10m/s)2 =

½ (100kg)(10m/s)2 =

½(50kg)(20m/s)2 =

  • Remember: 1 kg.m2/s2 = 1J
  • A 0.10kg bird is flying at a constant speed of 8.0m/s. What is the bird’s kinetic energy?
  • A 70.0kg man is walking at a speed of 2.0m/s. What is his kinetic energy?
  • A 50.0kg cheetah has a kinetic energy of 18,000J. How fast is the cheetah running?
  • ______is energy that is ______as a result of ______or shape.
  • Ex: Lifting a book increases its ______, but letting the book go turns the energy into ______.
  • Two forms of potential energy are ______and ______.
  • Potential energy that depends on an object’s ______is called ______.
  • This type of potential energy ______when an object is raised to a ______level.
  • Formula for potential energy

PE =

m =

g =

h =

  • Notice that ______either the ______of the object or its ______doubles its ______.

PE = mgh

(50kg)(9.8m/s2)(10m) =

(100kg)(9.8m/s2)(10m) =

(50kg)(9.8m/s2)(20m) =

  • The potential energy of an object that is ______is known as ______.
  • The major forms of energy are ______

______.

  • Each form of energy can be ______into other forms of energy.
  • The energy associated with the ______of everyday objects is ______.
  • Mechanical energy is the ______of an object’s ______and ______energy.
  • The ______potential and kinetic energy of all the ______in an object make up its ______.
  • When an object’s atoms move ______, its thermal energy ______and the object becomes ______.
  • ______is the energy stored in ______.
  • When bonds are ______, the released energy can do ______.
  • ______is the energy associated with ______.
  • ______is a form of energy that travels through ______in the form of ______.
  • The energy stored in ______is known as ______.

Section 15.1 Assessment

  1. Describe the relationship between work and energy.
  1. How is the kinetic energy of an object determined?
  1. What factors determine the gravitational potential energy of an object?
  1. When you heat a pot of water over a flame, what form of energy is added to the water?
  1. What kind of energy is represented by an archer stretching a bow string?
  1. Can an object have both kinetic energy and potential energy at the same time?
  1. A 60.0kg person walks from the ground to the roof of a 74.8m tall building. How much gravitational potential energy does she have?

Chapter 15 Energy

Section 15.2: Energy Conversion and Conservation

  • ______can be ______from one form to another.
  • The process of changing ______from one form to another is ______.
  • Ex: ______convert ______into ______and electromagnetic energy.
  • The ______states that energy cannot be ______or ______.
  • When energy changes from one form to another, the ______remains unchanged even though many ______may occur.
  • The ______of an object is converted to the ______of motion as the object ______.
  • A ______consists of a ______swinging back and forth from a rope or string.
  • ______undergoes constant conversion as a______swings.
  • When ______is small enough to be ignored, the total mechanical energy remains ______.
  • Formula for conversion of mechanical energy
  • At a construction site, a 1.50kg brick is dropped from rest and hits the ground at a speed of 26.0m/s. Calculate the gravitational energy of the brick before it was dropped.
  • A 10kg rock is dropped and hits the ground below at a speed of 60m/s. Calculate the gravitational potential energy of the rock before you dropped it.
  • A pendulum with a 1.0kg weight is set in motion from a position of 0.40m above the lowest point on the path of the weight. What is the kinetic energy of the pendulum at the lowest point?
  • Einstein’s ______, says that energy and mass are equivalent and can be ______into each other.
  • In other words, ______is released as matter is ______, and ______can be ______from energy.
  • The ______has been modified to say that ______are always conserved.

Section 15.2 Assessment

  1. What does the law of conservation of energy state?
  1. As an object falls in free fall, what energy change is taking place?
  1. What did Einstein conclude about the relationship between mass and energy?
  1. What type of energy change results when friction slows down an object?
  1. Describe the energy of a playground swing at its highest position.
  1. A 0.15kg ball is thrown into the air and rises to a height of 20.0m. How much kinetic energy did the ball initially have?

Section 15.3: Energy Resources

  • ______exist in limited quantities and cannot be replaced except over the course of ______.
  • Nonrenewable energy resources include ______.
  • Oil, natural gas, and coal are known as ______because they were formed underground from the ______of once-living ______.
  • Fossil fuels are relatively ______and are usually readily available, but their use creates ______.
  • ______are resources that can be replaced in a relatively ______period of time.
  • Renewable energy resources include ______

______.

  • Energy obtained from ______is known as ______.
  • As water flows downhill its ______can be used to turn ______that are connected to ______.
  • The downside is that ______prohibit ______from swimming upstream to______.
  • ______that is converted into usable energy is called ______.
  • Sunlight can be converted directly into electrical energy by ______.
  • Solar energy is ______,but for areas where ______are frequent, solar energy is less ______.
  • ______is thermal energy beneath the ______.
  • Geothermal energy is ______, but is not ______.
  • The chemical energy stored in ______is called ______.
  • Many people around the world burn ______to heat their ______or for ______.
  • A ______generates electricity by reacting ______.
  • The end product of fuel cells is ______, so they are ______.
  • Energy resources can be ______by ______energy needs and by increasing the ______of energy use.
  • Finding ways to use ______or to use energy more ______is known as ______.

Section 15.3 Assessment

  1. List the major nonrenewable and renewable sources of energy.
  1. What could be done to make present energy resources last longer?
  1. Why are coal, oil, and natural gas called fossil fuels?