Motion

Motivational Poster #1

Applying physics principles

How do you KNOW something moved?

• Frame of reference the background or object used for comparison. All movement is described relative to a frame of reference.

• Ex: a train takes off with you in it. To the people watching on the ground, it is the Earth. To you, it is the train.

• The most common frame of reference is the earth.

What is the frame of reference?

How do we seethe bullet going through the lemon?

Motivational Poster #2

Measuring Motion• Motion – a change in

position in a certain amount of time.

• Speed – the rate at which an object moves.

• Speed = Distance/Time

• Speed is measured m/sec or km/hr

Which animal is the fastest?

Let’s Practice…

1.At what speed did a plane fly if it traveled 150 m in 5 seconds?

2. At what speed did a boy run if he went 2 km in 20 min?

3. At what speed did a bird fly if he went from one tree to another (35 m) in 7 seconds?

Motivational Poster #3

Types of Speed• Constant speed: when the speed of an object

does not change. The graph is always a straight line.

• Average speed: describes the speed of motion when speed is changing; graph is a jagged line.

• Velocity – a speed in a given direction. – Ex: Speed 10m/sec

Velocity 10m/sec east

Constant speed

Average Speed

Where do you use this information?

Why is Velocity important toPilots?

Combining Velocities

• Rowing downstream 16 km/hr• Water 10 km/hr__+__________________________

26km/hr

Rowing upstream 16km/hr Water 10 km/hr_--__________________________ 6 km/hr

Motivational Poster #4

Tying it all together…

Acceleration• Acceleration – the rate of change in velocity; an

object accelerates if its speed, direction or both change

• Final velocity - original velocity Time

Ex: A car is traveling at 60 km/hr. It accelerates to 85 km/hr in 5 hrs. What is the rate of acceleration?

V(final) – V(original) t

85 – 60 = 5 km/hr/hr 5*If the acceleration is negative than the object is decelerating

(slowing down).

Graphing Acceleration

Acceleration

Deceleration

Calculating Speed

Motivational Poster #5

Motion Continued…• Momentum – depends on the

mass and velocity with which it is traveling.

• Momentum = mass x velocity• Ex: What is the momentum of a

5 kg blue-jay flying at 10 m/sec?• M = mv• M = 5 kg x 10 m/s• M = 50 kg/m/s

Transfer of Momentum

Momentum Example:

Motivational Poster #6

How can you use all this information?

Wait! Before you go…one more!