Physical Science: A Study Guide
• Free Fall
o Motion under the influence of gravitational force
o Neglects air resistance
o An object moving under the influence of gravity
only
o All freely falling objects fall with the same
acceleration,
on Earth, it is 9.8 m/s2
o Kinematic Equations:
o 𝒗𝒇 = 𝒗𝒊 + 𝒂𝒕
o 𝒗𝒇 𝟐 = 𝒗𝒊 𝟐 + 𝟐𝒂𝜟𝒀
𝟏
o 𝜟𝒀 = (𝒗𝒊 + 𝒗𝒇 )𝒕
𝟐
𝟏
o 𝜟𝒀 = 𝒗𝒊 𝒕 + 𝟐 𝒂𝒕𝟐
o Sample Problem:
o A construction worker accidentally drops a brick from a high scaffold.
a. What is the velocity of the brick after 4.0 s?
b. How far does the brick fall during this time?
o A tennis ball is thrown straight up with an initial speed of 22.5 m/s. It is
caught at the same distance above the ground.
a. How high does the ball rise?
b. How long does the ball remain in the air? Hint: The time it takes the ball
to rise equals the time it takes to fall.
o A man is standing on the edge of a 20.0 m high cliff. He throws a rock
vertically with an initial velocity of 10.0 m/s.
a. How high does the rock go? (Remember that at its max height v = 0 m/s)
b. How long does it take to reach its max height?
• Projectile Motion
o The motion of a body projected horizontally or at an angle other than 90 degrees
with the horizontal.
o This is motion that occurs in two dimensions:
a. Horizontal motion is at constant velocity
b. Vertical motion is accelerated by gravity
o Trajectory is the path of the projectile. It also follows a parabola that results from
the combined motions in the horizontal and vertical directions.
o Components of Projectile Motion
Horizontal Component Vertical Component
Uniform in motion Free fall
Projectile moves horizontally at a Change occurs in the vertical velocity
constant speed when air resistance is because of the influence of gravity
neglected.
• Free Fall
o Motion under the influence of gravitational force
o Neglects air resistance
o An object moving under the influence of gravity
only
o All freely falling objects fall with the same
acceleration,
on Earth, it is 9.8 m/s2
o Kinematic Equations:
o 𝒗𝒇 = 𝒗𝒊 + 𝒂𝒕
o 𝒗𝒇 𝟐 = 𝒗𝒊 𝟐 + 𝟐𝒂𝜟𝒀
𝟏
o 𝜟𝒀 = (𝒗𝒊 + 𝒗𝒇 )𝒕
𝟐
𝟏
o 𝜟𝒀 = 𝒗𝒊 𝒕 + 𝟐 𝒂𝒕𝟐
o Sample Problem:
o A construction worker accidentally drops a brick from a high scaffold.
a. What is the velocity of the brick after 4.0 s?
b. How far does the brick fall during this time?
o A tennis ball is thrown straight up with an initial speed of 22.5 m/s. It is
caught at the same distance above the ground.
a. How high does the ball rise?
b. How long does the ball remain in the air? Hint: The time it takes the ball
to rise equals the time it takes to fall.
o A man is standing on the edge of a 20.0 m high cliff. He throws a rock
vertically with an initial velocity of 10.0 m/s.
a. How high does the rock go? (Remember that at its max height v = 0 m/s)
b. How long does it take to reach its max height?
• Projectile Motion
o The motion of a body projected horizontally or at an angle other than 90 degrees
with the horizontal.
o This is motion that occurs in two dimensions:
a. Horizontal motion is at constant velocity
b. Vertical motion is accelerated by gravity
o Trajectory is the path of the projectile. It also follows a parabola that results from
the combined motions in the horizontal and vertical directions.
o Components of Projectile Motion
Horizontal Component Vertical Component
Uniform in motion Free fall
Projectile moves horizontally at a Change occurs in the vertical velocity
constant speed when air resistance is because of the influence of gravity
neglected.
