WORD SPLASH Write a story using

the words on the list Underline each word

used Circle words you’ve

never heard in RED Circle words you’re

familiar with but unsure of in YELLOW

Circle words you know well in GREEN

MOTION

frame of reference - comparing an object’s motion to another object Your house stays still as the cars drive past

a frame of reference is necessary in order to describe motion

motion change in your position compared to a frame of reference. as a train moves past a platform, people

on the platform see those on the train speeding by. when people on the train look at one another, they don't seem to be moving at all OR moving backwards

Distance the length of a path between two points.

GO METRIC: km, m, mm, cm, etc.

Speed distance traveled per unit of time S = d/t A car travels 70 km per hour

Choose units that make sense: m/s, km/h

Average speed- the total distance traveled, d, divided by the total time, t, it takes to travel that distance.

speed= distance/time Ex- on vacation: 60 km in 0.8

hr, and 35 km in 0.5 hr. What is your average speed?

Instantaneous speed the rate at which an object is moving at a given moment in time Speedometer in a car

**Average speed is computed for the entire duration of a trip, and instantaneous speed is measured at a particular instant.

Graphing Motion

The slope of a line on a distance-time graph is speed.

Velocity Velocity- the speed and direction in which an object is moving Velocity is a vector. Velocity is CALCULATED the same way as speed…

V = d/t

Acceleration

Acceleration-The rate of change in velocity Changes in speed, direction or both

Can Increase (positive) or decrease (negative)

acceleration = zero if moving at the same speed in the same direction

Constant acceleration is a steady change in velocity over time. the velocity of the object changes by the same amount each second

A jet taking off.

Calculating Acceleration

Acceleration = Change in velocity = (vf-vi)

time t

Vf = final velocityVi = initial (starting) velocity

Units for acceleration: m/s2 or km/hr2

Graphing Acceleration

The slope of a speed-time graph is acceleration Can be linear or

non linear graph

Force force is a push or a pull that acts on an object.   can cause a resting object to move

can accelerate a moving object Acceleration =changes in ____ and/or ____

Newtons(N)- unit for force

One N is the force that causes a 1 kg object to accelerate at a rate of 1 meter per second every second (1 m/s2). 1 N = 1 kgm/s2

You are carrying a bowl of soup on your cafeteria tray. As you walk towards your table, someone suddenly steps out in front of you. You stop quickly. Describe the motion of the soup in the

bowl after you stop. Explain why you think the soup behaves

like it did.

FORCE

NET FORCE – Combination of forces in the same direction or opposite directions

Ex. If two people are pushing a cart at the same time…

FORCE

Balanced force- when forces are balanced, net force = 0. No change in motion (arm wrestle)

Unbalanced force- causes a change in motion

Starter 2/2

Hold a sheet of paper up and let it fall to the floor.

1. Describe what happens in one lineHold a crumpled sheet of paper up and let it

fall to the floor2. Describe what happens in one line.

3. How do the motion of the flat and crumpled sheet compare? What makes this happen? (Answer in 2 lines).

FRICTION

Friction – force that opposes the motion of objects by contactStatic Sliding Rolling Fluid

GRAVITY

Gravity – force that attracts or pulls objects together Acts downwards toward center of Earth

Causes objects to accelerate as they fall

1. Explain the following in 1 to 2 lines:

Ms. Bell gets upset and pushes Mr. Hill. She also pushes Ms. Hawbaker with the same force. Ms. Hawbaker goes further from the push.

2. What factors can affect force?

Newton’s Laws

1st - An object at rest remains at rest OR an object in motion remains in motion,unless acted on by an outside force

Newton’s Laws

1st law is called the Law of Inertia.

Inertia- tendency of object to resist change in motion. seat belts, airbags, etc – these objects protect you from inertia.

Newton’s Laws

2nd – the acceleration of an object depends on the force acting on the object and the mass of the object

F= (m)(a) OR a= f / m

PRACTICE

F = (m)(a) How much force is required to move a car with a mass of 1200 kg at a rate of 3.0 m/s2?

What is the force on a 80 kg box accelerating down a ramp at 2 m/s2?

Newton’s Laws

Mass – measure of inertia, amount of matter in an object

Weight- force of gravity on an object

This formula is a substitute for F= (m)(a)… g = 9.8 m/s2 (on earth)

Units for weight = newtons (N)

Newton’s Laws

3rd – for every action or force, there is an equal and opposite reaction or force Bumper cars If the forces both act on the same object the object will not move (net force = 0)

MOMENTUM

•Momentum - describes how mass and velocity are affected by each other.

• units are kgm/s

•No velocity? no momentum!

•Conservation of momentum-

The loss of momentum in one object is the gain of momentum in another