Transcript Chapter 12 Lesson 1

Chapter 12
Lesson 2
Newton’s Laws (1st and 2nd)
Newton’s Video
I. Famous Scientists
A. Aristotle – Greek
1. force is required to keep an
object moving at a constant speed.
True / False
B. Galileo – Italian
1. moving objects, without
gravity, would continue to move.
True / False
C. Newton
1. 1665 – Years of work
2. Book  Principia
D. Newton’s 1st Law
1. Def – an object in motion stays in
motion. An object at rest will stay at rest.
2. Ex: Car crash (pg. 364)
3. Ex: Ball sitting on ground
4. Ex: Curved road…what happens?
E. Newton’s 2nd Law
1. Def – A force that acts on an object
causes the object to move in the
direction of the force.
a. Must be unbalanced
2. Rocket Demo
a. Using arrows to represent forces,
draw a model describing the Rocket
Demo.
b. Hypothesize: What will happen
when I add 100 grams of mass to
the rocket?
3. Formula
Force = mass x acceleration
F=ma
Force = Newton’s
4. How much force would it take to
accelerate a motorcycle to 5 m/s2 with a 200 kg
motorcycle and a 75 kg rider? (F = m x a)
F=?
M = 200 + 75 = 275
a = 5 m/s2
 F = 275 kg x 5 m/s2
 = 1375 Newton’s
In Class Problems…
1. How much force is needed to accelerate a car
at 8 m/s2 if the mass of the car is 1000 kg?
 8,000 Newton’s
2. How much force is needed to accelerate a dirt
bike 5 m/s2 if the bike has a mass of 50 kg
and the rider has a mass of 60,000 grams?
 550 Newton’s
3. Make up your own story problem with an
answer for class tomorrow.