The acceleration of an object is
directly proportional to the net force acting upon it. The constant
of proportionality is the mass.
F=MA
A=F/M
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F = Force = A push or pull M = Mass A= Acceleration = speeding up, slowing down or changing direction |
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Mass
= 5 kg
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Let’s assume that the wheels of a 5-kg car apply 10 N of force. What is the net force if friction and drag are negligible? The net force would
equal 10 |
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What is the acceleration of the car? |
Force |
= MA |
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10 |
= 5A |
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Acceleration = |
2 m/s2 |
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Mass = 6 kg
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What is the net force if the wheels of the 5-kg car apply
10 The net force would
equal 3 |
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What is the acceleration of the car? |
Acceleration |
= F/M |
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Acceleration |
= 3/6 |
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Acceleration = |
0.5 m/s2 |
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Mass = 10 kg
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A rocket is added to the car and applies an additional
force of 10 The net force would
equal 13 |
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What is the acceleration of the car? |
Acceleration |
= F/M |
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Acceleration |
=13/10 |
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Acceleration
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=1.3 m/s2 |
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Big masses are hard to accelerate. Big masses require big forces to change speed. |
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Small masses are easy to accelerate. Small masses require small forces to change speed. |
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Objects move in the direction they are pushed or
pulled. Objects accelerate more quickly when a greater force is used. |
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Assume
that both steam engines below apply the same amount of force.
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A heavy train has a difficult time accelerating. Big masses require big forces to change speed. |
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Acceleration = |
Force / Mass |
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Acceleration = |
100% / 100% |
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Acceleration = |
1 |
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When
the same force is applied to a less massive train its acceleration is
greater. Small masses require small forces to change speed. |
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Acceleration = |
Force / Mass |
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Acceleration = |
100% / 10% of the big train |
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Acceleration = |
10 times greater than the big train |
