## Electrostatics Practice

Worksheet 1 # 1-6… read more

Category: Physics 12

Worksheet 1 # 1-6… read more

This video is only 10 minutes but EXTREMELY dense. Consider playing it at 0.75X speed and pausing frequently to take notes. That’s right – you are taking notes on these videos, right?

And a demonstration of a single force calculation using Coulomb’s law, with some explanation of the equation.… read more

Written response:

Circular Motion:

1. 1600 N

2. 7.7 rpm

3. coefficient when “just about to slip” = 0.61, so mu = 0.82 is fine

4. 11 N

Gravitation:

5. 9.2 hours

6. 3.3E8 m/s (note this is faster than the speed of light – no escape!)

7.… read more

We can apply our new improved understanding of gravity to work out circular motion problems involving orbits:

https://www.flippingphysics.com/geostationary-orbit.html

And just like we needed a new equation for gravitational force, we need a new one for gravitational potential energy.

This could cause some people confusion… negative energy?!… read more

Finish up the practice sheet.… read more

Practice problems assigned so far in this unit:

Basic: # 1-9

Advanced # 1-3

The law of gravitation (a formula):

https://www.flippingphysics.com/universal-law-gravitation.html

A simple sample problem:

https://www.flippingphysics.com/mermaid-doughnut-gravity.html

A short simple one: max speed a car can take around a curve:

Note that when circles are oriented vertically, you have to consider gravity in addition to centripetal force. At the top of the circle it helps it, at the bottom it opposes it.… read more

A very wordy introduction and summary of the unit. You might need to pause, slow down, or replay parts.

A refreshing musical interlude: (note that this is NOT actually zero G… just zero normal force)

A very thorough explanation of strategy and misconceptions:

The test is on Monday. For review, complete the practice test and check your answers:

Multiple choice:

- A
- B
- C
- B
- B
- D
- B
- C
- B
- B

Written response:

- 6.6 m/s at 20.4 degrees N of E (according to diagram with up being N – this is called “S of W” in the problem)
- 80N
- 91000 Ns upwards
- 211 m/s to the right
- 390 m/s at 70 degrees S of W

Written solutions for the written response questions here:

We’ve mostly focused on using the component method – because it always works. We break down momentum vectors into x and y components, then we know that momentum is SEPARATELY conserved in the x and y directions. This gives us two equations to solve.… read more