momentum and newton’s 2 nd law of motion. momentum momentum - an object’s tendency to keep...
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Momentum and Newton’s 2nd Law of Motion
MomentumMomentum - an object’s
tendency to keep moving Determines how difficult it is to
stop the object’s motion
Formula: Momentum = Mass x Velocity
MomentumMomentum = mass x velocity
Momentum = 1.5-kg x 10m/s2
Force = 15 kg-m/s2 or 15 N
A 1.5-kg ball is thrown at 10 m/s2. What is the ball’s momentum?
MomentumExample:
A 100-kg fullback runs up the middle of the football field. He collides with a 75-kg defensive back running toward him. The more massive fullback is thrown back two meters. Although he has less mass, the defensive back has more momentum because he is moving faster than the fullback.
Momentum
Law of Conservation of Momentum - the total momentum of any group of objects remains the same, unless outside forces act on the objects.
Newton’s Second Law
An object’s acceleration depends on its mass and on the net force acting on it.
Formula:Net Force = Mass x Acceleration
or
F = ma
Newton’s Second Law
Force = mass x
acceleration
Force = 1700kg x 2m/s2
Force = 3,400 kg-m/s2 or 3,400N
How much force is needed to accelerate a 1,700 kg car 2 m/s2?
Newton’s Second Law
An object will have greater acceleration if a greater force is applied to it.
Example: If you push a child on a swing, the swing begins to move. The harder you push, the faster the swing accelerates.
Newton’s Second Law
The mass of an object also affects the acceleration of the object.
In other words:If it’s big, it’s going
to move slow
If you push it harder it is going to go farther
Newton’s Second Law
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