Student Resources—746

Watch Out Below
Real-World Question
How does air resistance affect the velocity
of falling objects?
Possible Materials
• tennis ball • chair
• racquetball • stopwatch
• paper
Procedure
1. Stand on a sturdy chair, hold a tennis
ball above your head, and drop the ball
to the floor.
2. Have a partner use a stopwatch to
measure the time it takes for the ball to
fall from your hand to the floor.
The Heat is On
Real-World Question
How can different types of energy be
transformed into thermal energy?
Possible Materials
• lamp
• incandescent light bulb
• black construction paper or cloth
Procedure
1. Feel the temperature of a black sheet of
paper. Lay the paper in direct sunlight,
wait 10 min, and observe how it feels.
2. Rub the palms of your hands together
quickly for 10 s and observe how they
feel.
Adult supervision required for all labs.
Extra Try at Home Labs
3. Drop a flat sheet of paper from the
same height and measure the time it
takes for the paper to fall to the floor.
4. Crumple the sheet of paper, drop it
from the same height, and measure the
time it takes for the paper ball to fall to
the floor.
Conclude and Apply
1. List the amount of time it took for each
of the objects to fall to the floor.
2. Infer how air resistance affects the
velocity of falling objects.
3. Switch on a lamp that
has a bare light bulb.
Without touching the
lightbulb, cup your
hand 2 cm above
the bulb for 30 s and
observe what you
feel.
Conclude and Apply
1. Infer the type of energy transforma
tion that happened on the paper.
2. Infer the type of energy transformation
that happened between the palms
of your hands.
3. Infer the type of energy transformation
that happened to the lightbulb.
EXTRA TRY AT HOME LABS 771
John Evans
Extra Try at Home Labs