Old photographic flashbulbs burn magnesium metal in a reaction that causes a flash of
brilliant white light. A photographer would need to take care not to suffer burned fingers
when trying to replace the hot bulb.
What best identifies the energy transformation that
occurs in the flashbulb?
A: chemical energy to electromagnetic energy and thermal energy
B: electromagnetic energy to chemical energy and thermal energy
C: chemical energy to electromagnetic energy
D: thermal energy to chemical energy - ANSWER: A: chemical energy to
electromagnetic energy and thermal energy
According to the law of conservation of energy, what will most likely happen in a closed
system?
A: Energy will be exchanged along with matter.
B: Energy will be exchanged, but matter will not be exchanged.
C: Energy will be created along with matter.
D: Energy will be destroyed, but matter will not be destroyed. - ANSWER: B Energy will
be exchanged, but matter will not be exchanged.
A generator contains a coil that spins to produce an electric current. How is energy
transformed by using a generator?
A. Thermal energy is transformed to potential energy.
B. Thermal energy is transformed to mechanical energy.
C. Chemical energy is transformed to electromagnetic energy.
D. Mechanical energy is transformed to electromagnetic energy. - ANSWER: D.
Mechanical energy is transformed to electromagnetic energy.
An arrow is fired at a target on a high wall. Which statement correctly describes the
change in the energy of the arrow as it moves toward the target?
A. The potential energy and kinetic energy remain the same.
B. The potential energy decreases as kinetic energy increases.
C. The kinetic energy decreases as potential energy increases.
The kinetic energy remains at zero, but potential energy increases. - ANSWER: c: The
kinetic energy decreases as potential energy increases
Which is the best example of potential energy?
A. holding a basketball in the air
B. rolling a ball across a flat table
, C. flowing electric current through a wire
D. turning on a flashlight in a dark room - ANSWER: A holding a basketball in the air
Which statement describes thermal energy?
A. the energy that is associated with electric fields
B. the energy that is stored in chemical bonds
C. the energy that is associated with the pull of gravity
D. the energy that is associated with temperature - ANSWER: the energy that is
associated with temperature
As gravity makes an object fall down toward the ground,_______ energy becomes
kinetic energy. - ANSWER: POTENTIAL
Which energy change best relates to a boulder that is rolling down the side of a hill?
potential energy transforming into kinetic energy
mechanical energy transforming into thermal energy
potential energy transforming into electromagnetic energy
mechanical energy transforming into electromagnetic energy - ANSWER: potential
energy transforming into kinetic energy
A welding torch produces a flame by burning acetylene fuel in the presence of oxygen.
The energy released from the acetylene fuel is then used to melt a metal.
Which energy transformation happens during this process?
Chemical energy turns into thermal energy.
Kinetic energy turns into potential energy.
Thermal energy turns into electromagnetic energy.
Potential energy turns into chemical energy. - ANSWER: Chemical energy turns into
thermal energy.
Which statement is correct about the law of conservation of energy?
Energy is created when water freezes.
Energy is destroyed when sugar is burned.
Energy stays inside molecules permanently.
Energy is transferred when atoms are rearranged. - ANSWER: Energy is transferred
when atoms are rearranged.
In a chemical reaction occurring in an open beaker, the reactants have a mass of 10.0 g
and contain 1000 J of energy. The products in the beaker contain a mass of 5.0 g and