1. GRAVITY What goes up, must come down??

2. Gravity Is it possible for some basketball players to “hang” in the air during a dunk? Give your opinion http://www.youtube.com/watch?v=vZqVq5LrdQQ Tuesday

3. WHAT IS GRAVITY? Gravity is a FORCE Gravitational attraction pulls all objects towards each other. The force can be STRONG or WEAK. The strength of gravitational force depends on : MASS & DISTANCE

4. THE RELATIONSHIP BETWEEN MASS, DISTANCE AND GRAVITATIONAL FORCE IF YOU INCREASE THE DISTANCE BETWEEN TWO OBJECTS DOES GRAVITATIONAL FORCE INCREASE OR DECREASE? WHAT IF YOU INCREASE THE MASS OF THE OBJECTS? Hint: think of the Sun and the Moon

5. Relationships As DISTANCE INCREASES, the gravitational force goes DOWN. As MASS INCREASES, the gravitational force goes UP. WHY does your gravitational force not pull objects toward you?

6. GRAVITY – fast facts ALL OBJECTS with mass exert gravitational force. Gravity causes falling objects to speed up (accelerate) as they fall : 9.8 m/s FASTER EVERY SECOND. Acceleration = 9.8 m/s 2 Gravity (and inertia) causes the Earth to orbit the sun and the Moon to orbit the Earth. The gravitational pull of the sun and the moon creates tides on Earth (2 high & 2 low tides per day)

7. WEIGHT Another name for gravitational force of objects near Earth’s surface is WEIGHT Remember Newton’s 2 ND LAW: F = M X A Because of gravity, objects fall at a constant ACCELERATION (9.8 m/s 2 ) So objects near the Earth surface have GRAVITATIONAL FORCE =MASSx9.8m/s 2 =WEIGHT

8. WEIGHT VERSUS MASS WEIGHT AND MASS ARE DIFFERENT! WEIGHT is a FORCE measured in Newtons. When you step on a scale, you are measuring gravitational force. Your weight changes depending on your location (Earth, the moon, etc). MASS: is the AMOUNT OF MATTER IN AN OBJECT and does NOT depend on location