Chapter 17-Newton’s Laws Gravity and Motion-The acceleration due to gravity is the same for all objects on Earth; this is 9.8 m/s/s Air resistance (fluid friction) slows down this acceleration Terminal velocity: the object falls at a constant velocity and stops speeding up.

1 st Law of Motion An object at rest or in motion will continue in that way until another force acts upon it. Example: Bowling pins will continue to sit at the end of the alley until someone rolls a bowling ball into them, knocking them down

2 nd Law of Motion An object acted upon by a force will accelerate in the direction of that force. a=net force/mass Force measured in N, or 1 kg m/s 2 Example: If you are pushed on a swing, you go forward, the direction of the push. Gravity brings you backwards, the direction of it’s pull.

3 rd Law of Motion For every ACTION, there is an opposite and equal REACTION. You push on a wall, it pushes back at you with equal force. So, if you walk into a glass door you didn’t realize was there, you definitely know it. Other examples: Pushing with your feet off the diving board; pushing a canoe paddle through water; a rocket launching from the earth.