This document discusses the principles of falling bodies and gravity. It covers Galileo's experiments which proved that all objects fall at the same rate regardless of mass. Formulas for displacement and velocity of falling objects are presented. An example problem calculates the velocity and distance fallen for a bungee jumper after 1.5 seconds. The magnitude of gravity on Earth is given as 9.8 m/s2. Activities on measuring reaction time and solving kinematic equations for falling objects are also described.

1. What goes up must go
down!
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2. Prepared by: Darwin P. Paran

3. Falling Bodies
Free Fall
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4. Gravity
• The attraction due to gravitation
that the Earth exerts on or near its
surface
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5. Christian Huygens
• First one to
determine the
magnitude of gravity
from the swing of the
pendulum using a ruler
and a good timepiece.
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6. The magnitude of gravity is
9.8𝑚
𝑠2
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7. • In the late 16th century, it was
believed that heavier objects fall
first to the ground than the lighter
ones.
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8. Galileo
• Proved that
regardless of
weight and air
resistance, the
rate of fall of all
falling bodies are
the same.
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9. Experiment of Galileo
Materials: metal ball, inclined plane, and a water timer
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10. How can we measure
the distance covered
and final velocity of a
falling body?
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12. Displacement of Falling
Bodies
𝑑 𝑦 = 𝑣 𝑦 𝑜
𝑡 +
𝑔𝑡2
2
Where:
dy is displacement
vyo is initial velocity
g is gravity ( 9.8m/s2)
t is time interval
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13. Velocity of Falling Bodies
𝑣 𝑦 𝑓
= 𝑣 𝑦 𝑜
+ 𝑔𝑡
Where vyf is final velocity.
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14. 𝑣 𝑦 𝑜
𝑣 𝑦 𝑓
𝑑 𝑦
Y
X
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15. Sample Problem:
• The time a male bungee jumper is
freely falling is 1.5 seconds.
– What is the velocity of the jumper at
the end of 1.5 seconds?
– How far does he fall?
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16. DISTANCE
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17. Given:
• vi = 0
• t = 1.5 s g = 9.8 m/s2
• 𝑣𝑓 = 𝑣𝑖 + 𝑔𝑡
• vf = 0 + (9.8m/s2)(1.5s)
• vf = 14.7 m/s or 15 m/s
• 𝑑 = 𝑣𝑖 𝑡 +
𝑔𝑡2
2
• d = (0)(1.5s) + (9.8
m/s2)(1.5s)2/2
• d = 11.025m or 11 m
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18. Reaction Time
• The time between stimulus and
response.
• Measure your reaction time.
..ActivitiesMy Reaction Time.pdf
• Challenge your reaction time through
paper bill challenge. (catch me if you
can)
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19. Quiz: ¼ sheet of paper
1. A rock fell from a cliff and reaches
the ground after 5 seconds.
Compute the:
a. distance or height of the cliff
to the ground?
b. final velocity of the rock
before reaching the ground.
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20. Quiz: ¼ sheet of paper
1. A ball is dropped from the 2nd floor
of a building and reached the ground
after 0.98 second. Compute the:
a. distance or height
b. final velocity of the ball
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