Universal Gravitation

February 5th, 2009

Gravitational ForceGravitational Force

Mutual force of attraction between particles of matterDo you exert a gravity force on the earth?

Field force that exists between two masses regardless of:The medium (stuff) that separates themTheir size or composition

What’s the difference between a field and a contact force?

Mutual force of attraction between particles of matterDo you exert a gravity force on the earth?

Field force that exists between two masses regardless of:The medium (stuff) that separates themTheir size or composition

What’s the difference between a field and a contact force?

Newton’s Law of Universal Gravitation

Newton’s Law of Universal Gravitation

Depends on the distance between two masses

Fg=G*m1m2/r2 Fg= force of gravity

G= constant of universal gravitation

G=6.673 x 10-11 Nm2/kg2

This is the stuff that keeps the planets in motion!

Depends on the distance between two masses

Fg=G*m1m2/r2 Fg= force of gravity

G= constant of universal gravitation

G=6.673 x 10-11 Nm2/kg2

This is the stuff that keeps the planets in motion!

Practice!Practice!

Find the distance between a 0.300 kg billiard ball and a 0.400 kg billiard ball if the magnitude of the gravitational force is 8.92 x 10-11 N

Find the gravitational force exerted on the moon (m=7.36 x 1022 kg) by Earth (m=5.98 x 1024 kg) when the distance between them is 3.84 x 108 m

Find the distance between a 0.300 kg billiard ball and a 0.400 kg billiard ball if the magnitude of the gravitational force is 8.92 x 10-11 N

Find the gravitational force exerted on the moon (m=7.36 x 1022 kg) by Earth (m=5.98 x 1024 kg) when the distance between them is 3.84 x 108 m

HomeworkThis will be collected next class

HomeworkThis will be collected next classP. 265

Practice 7I#1-3

Read p. 266-267 & Answer these questionsWhat is the formula used to calculate escape velocity?

Does the mass of the projectile matter?What is the escape velocity of a projectile from earth?Does a projectile require a high or low speed to escape from a body

with a low mass and large radius?What is the Schwarzchild radius?

Why can’t light escape from this point?Where is the closest black hole?

P. 271#38, 39, 40, 47

P. 265 Practice 7I

#1-3

Read p. 266-267 & Answer these questionsWhat is the formula used to calculate escape velocity?

Does the mass of the projectile matter?What is the escape velocity of a projectile from earth?Does a projectile require a high or low speed to escape from a body

with a low mass and large radius?What is the Schwarzchild radius?

Why can’t light escape from this point?Where is the closest black hole?

P. 271#38, 39, 40, 47