Page 69 - Science Course 1 (Book 2)

6. The transformation of electric energy to radiant energy and thermal energy when a f ashlight is turned on is
an example of energy (inef ciency, transfer).

7. There are no true (closed, recycled) systems because every physical system transfers some energy to the
environment.

8. The sound of a bus passing by is an example of an (open, ef cient) system because some chemical energy
is transformed to sound and other energy is transformed to (thermal, electric) energy and mechanical
energy.

9. Work occurs when a basketball player (holds, shoots) a basketball and also occurs when a hockey player
(moves, stops) the puck with a hockey stick.

10. A television set projecting color images is an example of a(n) (open, closed) system because some
energy is being exchanged within the (electrical system, environment).

Mo8-L4: Key Concept Check

Direction: Put a check mark in the column that describes each example. Then identify the type of energy
being transferred or transformed. (Hint: For transferred energy, you will only need to identify
the type of energy being transferred. For transformed energy, you will need to identify the initial
energy and the new type of energy after the transformation.)

Type(s) of Energy
Transferred Transformed Being Transferred
Energy Energy
or Transformed

1. A tennis racket applies force
to a tennis ball when it hits the
ball, forcing the ball to move
forward.

2. A softball player throws a
ball toward f rst base.

3. Fuel in an engine burns, and
the car moves forward.

4. A runner eats an energy bar
and later that day runs in the
100-m race.

5. Lights glow in the night
sky when the power switch is
turned on.

6. A hockey stick stops a
sliding puck and sends it
toward the goal.

7. A truck roars by a row of
apartments on a quiet evening.

8. A song plays on the radio.

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