# Understanding Gravity - Investigating the Force of Attraction

This investigation explores the concept of gravity and its role in force and motion. Gravity is a force that pulls masses toward each other, and on Earth, it is the force of

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## About Understanding Gravity - Investigating the Force of Attraction

PowerPoint presentation about 'Understanding Gravity - Investigating the Force of Attraction'. This presentation describes the topic on This investigation explores the concept of gravity and its role in force and motion. Gravity is a force that pulls masses toward each other, and on Earth, it is the force of. The key topics included in this slideshow are . Download this presentation absolutely free.

## Presentation Transcript

Slide1GravityGravity Gravity Gravity 8th  Grade 8th  Grade Investigation  7 Investigation  7 Force  and  Motion Force  and  Motion

Slide2Gravity• Gravity : a force pulling masses toward each other. – On Earth, the gravitational force is the force of attraction between Earth (one of the masses) and another object.

Slide3Gravity• The strength of the gravitational force depends on the size of the masses. – Larger objects pull with more force than do smaller masses.

Slide4Free Fall• Gravity is the force that makes things fall toward Earth. – Because the force applied all of the time, any object that is not retarded by another force will accelerate toward Earth =  Free Fall .

Slide5Acceleration Due toGravity • All objects fall with the  same acceleration when they are in  free fall (9.8 m/s 2 ). – Objects like cotton balls & feathers don’t fall as fast as rocks and shoes because they are slowed by  air resistance .

Slide6Air Resistance• Air resistance is like friction, it acts to  resist motion. • The force of  air resistance  acts in the direction  opposite  to the force of gravity. – The net force pulling the cotton ball toward Earth is less than the force of gravity, so it takes longer to fall than an object in free fall.

Slide7Free-Fall• The force of gravity makes heavy and light objects free-fall at the same acceleration. – Galileo discovered that objects of different masses fall together, hitting the ground at the same time. – Example: Foil ball vs. paper ball.

Slide8Force of Gravity• The force of gravity accelerates objects in free fall and objects rolling down hill. • Gravity is a universal force of attraction between masses.

Slide9Acceleration Due toGravity • Example: Speedometer - measures speed. – If a boulder dropped from a cliff, it would fall 10 m/s faster than it was in the previous second due to gravity.

Slide10Acceleration Due toGravity • The change of velocity in the boulder example is the acceleration due to gravity. • The velocity of an object during its fall can be calculated by the velocity equation:  v  =  a  x  t