# AP Physics with Hansenator - Circular Motion and Gravitation

## Circular Motion

We are not only going to talk about the motion in this lesson, but also the forces associated with the motion. There is certain geometry about circles that you need as well as a basic knowledge of Kinematics, so study up folks!

## Today's Equations

#### Circles

#### Kinematics

#### Circular Motion

#### Gravitation

#### Kepler's Third Law

## Many Examples

- Assume the moon orbits the Earth in a circular orbit with a radius of 3.84x10^8 meters. It takes 27.3 days to make a full orbit. What is the centripetal acceleration of the moon?

- A car is driven around a circular track with a radius of 3.5 meters at a speed of 15 km/h. (a) What is the force on an .18-kilogram object in the car? (b) When the car is headed due North, the object is thrown out of the car upward with a speed of 5.0 m/s from the car (no longer acted on by the car). Where must a person be to catch this ball, if it was thrown from the same distance from the ground it was thrown?

(a)

(b) - A bicycle rides around a rounded track at a speed of 12.67 m/s. The radius of the track is 60.0 m. What is the centripetal acceleration of the car?

- Titan, the largest moon of Saturn, has a mean orbital radius of 1.22x10^9 m. The orbital period (T) of Titan is 15.95 days. Hyperion, another moon, orbits at a mean radius of 1.48x10^9 m. Use Kepler's third law of planetary motion to predict the orbital period of Hyperion in days.

- Two identical bowling balls are placed 1.0 m apart. The gravitational force between them is 3.084*10^-9 Newtons. (a) Find the mass of the bowling balls. (b) Compare the weight of the first ball with the gravitational force of the second ball.

(a)

(b)

completelyanon (56)7 years agoI really enjoyed your post, thank you for sharing with us. Enjoy the vote!

rufans (68)7 years agoYea ,his blog is eductive 👍

hansenator (57)7 years agoThank you anon! Hope all is well at your end too!

splash-of-angs63 (49)7 years agoVery important equations for motion and gravitation.we can calculate Vescape=√(2×g×r) to calculate easily as value of 'g' is easy to calculate than that of 'G'

Nice post. Great work :)

hansenator (57)7 years agoHey splash-of-angs63! Thanks again for the comment. Check your equation. Best wishes to you!

splash-of-angs63 (49)7 years agoYeah it is also a right equation. If you calculate by putting the values it will come accross 11,182 m/s i.e 11.2(approx) km/s

Thank you for your kind reply. I will be a daily reader of yours as I am too a lover of science :)

hansenator (57)7 years agoGlad to hear it. Yeah. Takes a lot to escape a planet. Haha.

djmalith (56)7 years agoLearned this Equations when I was doing my Advanced Level in Combined Mathematics..You remind it to me @hansenator..

I'm really grateful in your effort..

upvoted and Steem on..😊👍👌

hansenator (57)7 years agoThank you djmalith! Many more to come! See you around!

djmalith (56)7 years agoAny time..😊Yesterday forget to follow you.. Now followed you and will give my support to your blog.. Also many thanks for your support on my blog..

Cheers..👍

hansenator (57)7 years agoAnytime djmalith! Thank you for the support as well!