Forces and Motion Unit F

Ant Maze When things are in MOTION, we need to know: 1.Distance 2. Direction

Measurement Metric –Length: meter –Volume: liter –Mass: gram All but 3 countries use the metric system. Used to measure with BODY PARTS 1000 m = 1 km 100 cm = 1 m 10 mm = 1 cm

Speed Speed = distance ÷ time Ex. Michael walked 6 mi in 3 hours. His speed was 2 mi/hr (or 2 mph)

Velocity, Acceleration, and Deceleration Velocity – speed and direction –Ex. (60 mph South) Acceleration – any change in velocity (speed or direction) Deceleration – slowing down 4:16

Mass vs. Weight Mass –amount of stuff in an object –measured in g or kg Weight –measures the force of gravity pulling on an object –measured in Newtons (N) (or pounds) The farther we are from the center of the Earth, the less gravity pulls on us (so the less we weigh) 2:04

Gravity Gravity – pull on objects from Earth’s core Objects fall to the ground at the same rate, no matter what size they are (assuming air resistance is not a factor, or if you are in a vacuum. ) As an object falls to the ground, the speed of that object increases. 7:43

Newton’s 1 st Law Law of Inertia Objects in motion stay in motion; Objects at rest stay at rest until acted upon by another force. 6:04 2:15

Newton’s 2 nd Law Force = mass x acceleration Acceleration depends on the mass of the object and the strength of the force –The larger the mass, the more force you’ll have to use. –The harder you push, the faster the acceleration 2:34

Newton’s 3 rd Law When one person lands on a trampoline, the other person bounces up. For every action there is an opposite and equal reaction. 3:00

Momentum Tells the combined effect of an object’s mass and velocity. Momentum will be transferred in a collision.

Newton’s 3 Laws Bumper Car Physics

Planes Thrust - push produced by spinning propellers. Lift - upward force caused by differences in air pressure that allows planes to rise into the air Drag- resistance to forward motion caused by air

Boats Buoyancy – ability of liquids to keep objects afloat Density –If the density of an object is less than 1 gram, it will float in water. –Objects are more likely to float if you can decrease the density.

References Basics of Physics: Exploring the Laws of Motion. United Learning (2004). Retrieved March 6, 2007, from unitedstreaming: Exploring Gravity. United Learning (1993). Retrieved March 6, 2007, from unitedstreaming: