Energy Review 1

Which of the following describes the energy conversions in a car's engine? 

• chemical to thermal to mechanical
• chemical to electrical to mechanical
• thermal to mechanical to chemical
• kinetic to potential to mechanial

According to the graph, which of the following is the best estimate for the kinetic energy of the rock after it has fallen for 1 s? 

• 100 J 
• 50 J
• 200 J 
• 0 J 

At its highest point, a pendulum is 1.2 m above the ground and has a GPE of 62 J. If the GPE is 10 J at its lowest point, what is the pendulum's KE at this point? 

• 0 J 
• 31 J 
• 62 J 
• 52 J 

When an energy transformation occurs, which of the following is true? 

• Mechanical energy doesn't change. 
• Mechanical energy is lost. 
• The total energy doesn't change. 
•  Mass is converted into energy. 

Ignoring friction, at what point in its motion is the kinetic energy of the ball at a maximum? 

• just before the bat strikes it
• just before it hits the ground
• just after the bat strikes it
• at the top of the arc

A rock dropped from a cliff has greater KE just before it reaches the ground than it did at the top of the cliff. Which of the following explains this fact? 

• The rock's mass decreases as it falls. 
• Falling has increased the rock's total energy. 
• The rock's GPE has been converted into KE. 
• Chemical analysis will reveal that the rock's chemical energy has been consumed. 

In a coal burning power plant, coal is burned to heat steam to turn a turbine. The turbine generates power that is sent to homes and businesses. Order the energy transformations of the power plant. 

• chemical, mechanical, electrical
• electrical, chemical, mechanical
• mechanical, chemical, electrical
• mechanical, electrical, chemical

What do all of the processes listed here have in common? 
  sawing a piece of wood
  lighting a match
  turning on a light bulb

• All transform into a form of energy from chemical energy.
• All transform into a form of energy from electrical energy. 
• All transform a form of energy into light energy. 
• All transform a form of energy into heat energy. 

Which is an example of energy from chemical bonds being formed or broken and transformed into energy of motion? 

• lighting a match
• turning on a battery operated toy car
• pushing a button on the TV remote control
• the wind turning the blades of a windmill

Which of the following describes how energy is converted when a cat knocks a plant off a counter? 

• The GPE of the cat is converted into KE. 
• The KE of the cat is converted into GPE. 
• The GPE of the plant is converted into KE
• The KE of the plant is converted into GPE.