toc: newton’s laws of motion 12/1/2015. set up your foldable like this!!!!

TOC: Newton’s Laws of Motion12/1/2015

Set up your foldable like this!!!!

Newton’s First Law of Motion

• What does this really mean?– An object at rest will stay at rest, and an object in motion will stay in motion

at constant velocity, unless acted upon by an unbalanced force.

• Inertia– Tendency of an object to resist a change in motion– Inertia means that the object’s motion will stay constant in terms of speed

and direction– Depends on the mass of an object– Does NOT depend of the presence of gravity

• An object’s inertia is the same on Earth and in space

– Objects with a greater mass have greater inertia

Examples of the Law of InertiaIf an object is in motion, it will keep going until something stops it. How would vehicle restraints help in this situation?

http://www.nsf.gov/news/special_reports/football/lawofmotion.jsp

Newton’s 1st law demo

• https://www.youtube.com/watch?time_continue=100&v=0oyJmFe3ffg&noredirect=1

• https://www.youtube.com/watch?v=1_EV2KEnqoQ

Check for Understanding

Which object has the greater inertia?

• Restate Newton’s First Law of Motion in your own words.

• What is inertia?

• What are some examples of Newton’s First Law of Motion?

TOC: Newton’s Laws of Motion12/2/2015

Newton’s first law REVIEW

Summarize what the law states.

What does an object at rest need for it to move?

What is another name for Newton’s first law of motion?

What is inertia?

What causes a moving object to stop moving?

The (more/less) mass an object has, the harder it is to move.

The (more/less) mass an object has, the harder it is to move.

An object with a smaller mass has LESS INERTIA

Easier to accelerate a small mass

More difficult to accelerate a large mass that has more inertiaF = force (N)m = mass (kg)a = acceleration (m/s2)

Newton’s 2nd LawThe acceleration of an object depends on the mass of the object and the amount of force

applied

Part 1: Acceleration depends on mass

Acceleration of an object decreases as its mass increases

Acceleration of an object increases as its mass decreases

Which would be easier to push?

WHY?

Newton’s law with MATHFormula:

F= M x A Force

acceleration

mass

UNITS

acceleration: m/s² (meters per second squared)

force: N (Newtons)mass: kg (kilograms)

More examples of the Law of Force and Acceleration

Roller Coaster http://iws.collin.edu/mbrooks/student%20research/projects/Rollercoaster%20Simulation/index.html

Baseball: home run vs. bunt

http://www.youtube.com/watch?v=kZMuMd64j6U

http://www.youtube.com/watch?v=FiMIY3J5XTw

Footballhttp://www.nsf.gov/news/special_reports/football/newtonsecondlaw.jsp

Check for Understanding

• Restate Newton’s Second Law in your own words.

• Which would require a greater force to accelerate? WHY?– A hockey puck on ice or a hockey puck on uncut grass?– An empty suitcase or a suitcase full of bricks?

• If the mass of a rock is doubled, what happens to its acceleration if the force does NOT change?