Download Acceleration and Momentum

ACCELERATION AND MOMENTUM
WHAT IS THE SECOND LAW OF MOTION?
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Newton’s Second Law of Motion- the acceleration of an
object is related to the object’s mass and to the amount
of force applied to the object.
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𝑓𝑜𝑟𝑐𝑒 = 𝑚𝑎𝑠𝑠 × 𝑎𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛
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A large force on an object with a small mass results in a
large acceleration.
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A small force applied to an object with a large mass
causes small acceleration.
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When a force is applied, objects with less mass
accelerate more quickly.
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2 results of Newton’s Second Law:
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For a given net force, objects with a greater mass have less
acceleration.
For objects of a given mass, a greater force results in a
greater acceleration.
WHAT IS NEWTON’S THIRD LAW OF MOTION?
• Newton’s Third of Motion- For every
action, there is an equal and opposite
reaction.
• Anytime one object exerts a force on
another object, a pair of forces acts.
• An action-reaction pair of forces.
• The two forces have the same strength but
act in opposite directions.
• If the objects have different masses, the
object with less mass will move more but
still exert the same force.
WHAT IS MOMENTUM?
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Momentum- the quantity that measures both the mass of the
object and how fast the object is moving.
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𝒎𝒐𝒎𝒆𝒏𝒕𝒖𝒎 = 𝒎𝒂𝒔𝒔 × 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚
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An object is easier to stop when it is moving slowly compared
with when it is moving rapidly.
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The greater the object’s momentum, the more force and time it
takes to bring it to a stop.
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A baseball has more momentum than a tennis ball when the 2
are traveling at the same speed because the baseball has more
mass.
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A tennis ball can have more momentum than a baseball if the speed
of the tennis ball is great enough.
HOW IS MOMENTUM CONVERTED?
• Conservation of momentum- the total
momentum does not change if there is
no outside forces acting on the system.
• Look at the picture. Before the girl
pushed the boy, the total momentum of
the skaters was zero. The total
momentum cannot change.
• The girl must have enough momentum to the
left to cancel the boy’s momentum to the
right.
HOW DO WEIGHT AND MASS COMPARE?
• The weight of an object depends on its
location in the universe and how much
gravity is pulling on it.
• The mass of an object does not change.
WHAT IS WEIGHTLESSNESS?
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When something is freefalling, a scale would not be able to
read its weight, so the object is weightless.
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When an astronaut is in space, they are freefalling..
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To simulate weightlessness, you can work underwater because
water reduces your weight when your submerged.
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Gravity and inertia keep a satellite in orbit.
Since everything in the spacecraft is falling together, the weight
of any object cannot be detected.
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Both motions happen continuously, and they combine to keep a
satellite in a curved path.
Placing a satellite in orbit requires accelerating it to a sideways
velocity great enough to keep its path of motion from colliding with
the surface of the Earth.