1 / 15

# Stop Faking It - PowerPoint PPT Presentation

Stop Faking It!. Force & Motion. Newton’s First Law of Motion. Objects in motion tend to stay in motion until something “hits” them Objects at rest tend to stay at rest unless something “hits” them Let’s test it - Use a ball and try for yourself!. You may have noticed. . . .

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about 'Stop Faking It' - london

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### Stop Faking It!

Force & Motion

• Objects in motion tend to stay in motion until something “hits” them

• Objects at rest tend to stay at rest unless something “hits” them

• Let’s test it - Use a ball and try for yourself!

### You may have noticed. . .

Things tend to keep on doing whatever they’re doing until something else “hits” them.

• When you were pushing, pulling, nudging, or blowing on the ball you were causing the “hits” that moved the object.

• These things, along with other things that change motion, are called forces.

• INERTIA

• An objects tendency to keep doing what it’s doing is its inertia.

• An object with lots of inertia requires more force to change its motion.

• An object with less inertia requires less force to change its motion.

• A FORCE called FRICTION

• Your test objects stop because they “hit” other objects (which could even be air particles). These “hits” cause friction and this causes the object to come to rest.

• Mass - measure of an object’s inertia: big inertia=big mass, small inertia=small mass

• A force acting on an object = mass of the object x acceleration of the object

• F=ma

• Larger force on small mass=large acceleration

• Obtain a meter stick, a ball, and a timing device.

• Start rolling the ball and begin timing when the ball reaches one end of the meter stick and stop timing when it reaches the other end.

• Record the distance (I meter) and the time.

• To calculate the speed of the marble, divide the distance traveled by the time it took to cover that distance. That is the object’s speed!

• Speed can be written using ”s” for speed or “r” for rate, or “v” for velocity.

• Distance traveled can be “d”; time can be represented by “t”

• s= d/t, r=d/t, v=d/t,

• Just know what the letters mean!

Velocity-tells how fast something is going and its direction (for example 65 mph North)

Vectors-arrows that can show velocity, magnitude (size), and direction.

Average speed is the what you get from s=d/t.

Instantaneous speed is your speed at a given instance in time.

Acceleration is a change in velocity (i.e.. Change in direction or speed or both) For example, a car speeding up(which is why they call it an accelerator on the car)

Another equation for you: acceleration=change in velocity/time for the change

Your body can detect changes in acceleration.

The earth’s pull (or force) on things

(it is also a force that exists between all objects)

Let’s test it.

Drop two things.

What happened?

They should have hit the ground at about the same time

When gravity is the only force applied, all objects have the same acceleration

Mass: A measure of an object’s inertia--how hard it is to change the motion of an object

If you change gravity, the mass would stay the same.

Weight: The force that gravity exerts on an object

If you change gravity, the weight would also change.

Mass vs. Weight

### Can distant objects influence our daily lives?

Because of gravity, you have a stronger attraction to things closer to you. You’ll be more attracted to something located on Earth than something located on Jupiter.

### Are astronauts really weightless when they orbit the Earth?

No, because weight is the force of Earth’s gravity and under normal conditions you are not ever totally away from that force.

### How do other examples of Gravity affect things on Earth?

Everything exerts some type of gravitational force on everything else.

One example: The gravitational forces between the moon and the waters found on Earth are responsible for the things we call Tides!

-