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Newton’s 2 nd Law. In this lesson, we will be focusing on Newton’s 2nd Law of Motion. This law is all about the connections between force , mass , and acceleration . Let’s find out more from the characters in Eureka. 3 2nd Law/Speed. 2 kg. 1 kg. 1 X. 2 X. The red ball has twice
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Newton’s 2nd Law
In this lesson, we will be focusing on Newton’s 2nd Law of Motion. This law is all about the connections between force, mass, and acceleration. Let’s find out more from the characters in Eureka.
2 kg 1 kg 1 X 2 X The red ball has twice the mass of the blue ball So.... to make them move at the same speed, what must happen to the force? ?
3 kg 6 kg 1 kg 20 X 20 kg 1 X 3 X 6 X FORCE is proportional to MASS Let’s try some other masses… ? ? ?
1 kg 1 kg 1 X 2 X What if both balls have the same mass, but the speeds are different. To double the speed, what must happen to the force? ? 20 km/hr 40 km/hr
1 X 1 kg 1 kg 1 kg 1 kg 3 X 2 X 4 X 1 X 1 X So... FORCE is proportional to CHANGE OF SPEED.... ? 20 km/hr 20 km/hr 40 km/hr ? ? 60 km/hr 80 km/hr
The amount of force needed depends onmass AND change of speed Let’s sum up what we know so far… If we double mass, we ______ force If we double change of speed we ______ force double double Ready for a brain check?
1. If mass of an object increases, what must happen to amount of force to move or stop it? A. increases B. decreases C. stays the same
2. To increase the speed of an object, what must happen to the amount of force? A. increases B. decreases C. stays the same
Let’s look at this idea of change of speed a little more… 4 Acceleration 1
The object starts out slowly, then goes faster, faster, faster…until it reaches top speed. Therefore, it’s all about how quickly it changes speed or the “rate of change of speed”. The word that means “rate of change of speed” is acceleration…
This means we can write Newton’s 2nd Law as “force varies with mass and acceleration” The key idea of this Law can also be turned into an equation: Force = mass x acceleration (F=ma)
FMA Live! Fma Live 2nd Law
Force = mass x acceleration F = ma In an equation, changing one variable means another variable must also change. If... What happens to… F = m a F? F = m a a?
Let’s try some more… If... What happens to… 1. F = m a a? 2. F = m a a? 3. F = m a F? 4. F = m a a?
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