Presentation on theme: "B.stored Unlike kinetic energy, potential energy is b.stored."— Presentation transcript:
b.stored Unlike kinetic energy, potential energy is b.stored
a. work Exerting a force on an object that causes the object to move is called a. work
c. power The rate at which work is done is called c. power
a.kinetic energy. The energy associated with motion is called a.kinetic energy.
c.mass and speed What two factors affect kinetic energy c.mass and speed
b.no energy is destroyed in the process. The law of conservation of energy states that when one form of energy is transformed into another, b.no energy is destroyed in the process.
b.nuclear energy. What type of energy powers the sun? b.nuclear energy.
c.sound energy. You hit a drum and hear a sound. What type of energy allows you to hear the sound? c.sound energy.
b.nuclear energy. Energy stored in the nucleus of an atom is called b.nuclear energy.
Energy Energy is the ability to do work or cause change.
mass A large truck and a small car are moving at the same speed. The truck has greater kinetic energy because its mass is greater.
thermal (heat) A toaster transforms electrical energy into thermal (heat) energy to toast the bread.
power The amount of energy transferred in a unit of time is called power.
potential A book sitting on a shelf has potential energy.
joules The SI unit for measuring energy is joules.
work Ben and Tim race 1 lap around a track. Tim won even though both runners did the same amount of work.
Which letter represents the position at which the basketball has the greatest potential energy? Explain. Point C. At this point, which is the highest point, all of the ball’s energy is gravitational potential energy. The ball does not have kinetic energy because it is not moving at this point.
Which letter represents the position at which the basketball has the greatest kinetic energy? Explain. Point E. As the ball falls from C to E, potential energy is converted to kinetic energy. The velocity of the ball increases as it falls, which means that the ball attains its greatest velocity, and thus its greatest kinetic energy, at E..
Which has the greater kinetic energy, a 10- kg object traveling at a speed of 2 m/s or a 5-kg object traveling at a speed of 4 m/s? Explain. ½ X 10 X 2 2 = ½ X 10 X 4 = ½ X 40 = 20 Joules ½ X 5 X 4 2 = ½ X 5 X 16 = ½ X 80 = 40 Joules.
Is the potential energy of the pendulum increasing or decreasing at position E? Explain. Neither. The potential energy of the pendulum reaches its maximum value at position E, and is neither increasing nor decreasing at that point..
Compare the sum of the kinetic and potential energies of the pendulum at position A to the sum at position C. (Ignore friction.) Point A is a point of maximum potential energy and minimum kinetic energy. Point C is the point of maximum kinetic energy and minimum potential energy. According to the law of conservation of energy, the sum of the kinetic and potential energies of the pendulum is constant, assuming no losses from friction. So the potential energy at A is equal to the kinetic energy at C..