WORD SPLASH Isaac Newton Motion Frame of reference speed velocity distance constant graph acceleration car time Isaac Newton Force 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
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.
The slope of a line on a distance-time graph is speed. Graphing Motion The slope of a line on a distance-time graph is speed.
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-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 velocity Vi = 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 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 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.
Ex. If two people are pushing a cart at the same time… 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…
Unbalanced force- causes a change in motion 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 line Hold a crumpled sheet of paper up and let it fall to the floor 2. 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 – force that opposes the motion of objects by contact Static Sliding Rolling Fluid
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 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
1st law is called the Law of Inertia. 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
What is the force on a 80 kg box accelerating down a ramp at 2 m/s2? 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?
Mass – measure of inertia, amount of matter in an object 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 - 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