Like this presentation? Why not share!

# 2.3 newton´s first and second laws

## by luzmaria_fabre on Dec 07, 2012

• 549 views

### Views

Total Views
549
Views on SlideShare
549
Embed Views
0

Likes
0
19
0

No embeds

### Accessibility

Uploaded via SlideShare as Microsoft PowerPoint

## 2.3 newton´s first and second lawsPresentation Transcript

• Chapter 2: Forces Miss Luzma Fabre
• Section 3: Newton´s First and Second Laws If an object is not moving, it will not move unless a force acts on it
•  If an object is already moving, it will continue to move at a constant velocity until a force acts to change either its speed or direction
• The First Law of Motion (or law of inertia) Newton´s first law of motion states that an object at rest will remain at rest, and an object moving at a constant velocity will continue moving at a constant velocity, unless it is acted upon by an unbalanced force
•  Inertia Is the tendency of an object to resist a change in motion Ex: moving forward in your seat when the car stops
•  Inertia depends on mass The greater the mass of an object is, the greater its inertia, and the greater the force required to change its motion Ex: full grocery cart vs empty grocery cart
•  How does Newton´s first law explain what happens to passengers when a car stops quickly?
• The Second Law of Motion
•  Mass= 55 kg Acceleration= 2 Net force (F m/s2 net)= ?
•  Changes in force and mass Ways to increase acceleration: Mass or Force
• Practice problems1. What is the net force on a 1000 kg object accelerating at 3 m/s2?2. What net force is needed to accelerate a 25 kg cart at 14 m/s2?3. What is the mass of a car that accelerates at a rate of 5 m/s2 due to a force of 4000 N?4. What is the acceleration of a 0.15 kg hockey puck that receives a net force of 1.8 N?