Newton's Laws of Motion
This video covers those magical three Newton's Laws: Newton's First Law, Newton's Second Law, and Newton's Third Law. He was very creative with the names, that Newton guy.
Monthly Archives: February 2017
This chapter covers those magical three Newton's Laws: Newton's First Law, Newton's Second Law, and Newton's Third Law. He was very creative with the names, that Newton guy.
Units of Force (Newtons)
These days, Newtons are the only unit of force that any physics profs seem to use. But that's actually good for you, because even though they're funky when you first see them, by the end of this video you'll see that as long as you always use kg and m/s2 in all your calculations, Newtons are easy!
Contact Forces vs Field Forces
This video quickly explains the difference between contact forces and field forces, and gives you a few examples of each.
Net Force & Equilibrium
This video explains what "net force" is, at least for physics (not sure about fishing). Bad news: it's a vector sum, so you'll have to use X & Y components! But you've been to that rodeo before, like in projectile problems, so should be plug and chug at this point. Also defined: equilibrium, and how a car can be at equilibrium while going 50 mph down the highway.
Mass vs Weight
This quick video explains the difference between mass and weight, and gives you a couple of examples that will come in handy if you're answering a short answer question about it!
Common Forces You Should Know
This video briefly explains and gives you the basic formulas for a bunch of forces you'll be seeing a ton in the forces section of physics: Tension, Springs (Hooke's Law), Weight (gravity), Normal Force, and Friction. The most useful of those is probably normal force, since that's the one with the least helpful name.
This chapter covers all of the basic vocab and concepts that you could need for multiple choice and short answer questions about forces. Lots of vocab and intro to forces you should know: Tension, Springs (Hooke's Law), Weight (gravity), Normal Force, and Friction. Also covered are the difference between mass and weight, and contact and field forces.
Linear Velocity In Circular Motion
In centripetal acceleration problems, sometimes they just give you velocity (the "v" in a=v2/r). However, often they give you that speed in another form such as RPM (revolutions per minute), Hertz (Hz, revolutions per second), or period of orbit (either orbits per year or years per orbit). This video is about how to convert those funky units into the linear velocity you want (m/s). For more, check out our unit conversion & dimensional analysis videos.
Centripetal Force vs Centripetal Acceleration
Later in physics, we'll have a bunch of videos on advanced centripetal force problems. This video is only meant to introduce the topic in the way you might see it in the kinematics section of your book, which is where books usually first introduce the centripetal force formula (a=mv2/r). Examples include: how fast you can swing a yo-yo before its string breaks, and the lateral force created by a car going around a turn.
Centripetal Acceleration & Satellite Orbit Problems
This video covers a variety of centripetal acceleration problems. We start with the basics of the centripetal acceleration formula (a=v2/r). Then we get into common examples: we calculate the speed a roller coaster should go over a 15-m radius hill such that it barely doesn't leave the tracks, and we calculate the velocity a satellite must have to maintain a circular orbit. Fun fact: both examples require setting centripetal acceleration equal to gravitational acceleration(g)!
Tangential vs Radial Acceleration
While most physics classes at least mention this topic, most don't dwell on it too much. The main thing is that you'll want to know what the terms "radial" and "tangential" mean, because those labels are often used in a wide variety of word problems, from rotating bodies to forces to torques to statics.
Centripetal vs Centrifugal (Fictitious) Forces
This video explains the basics of the centripetal acceleration formula (a=v2/r), then it gets into explaining the difference between centripetal and centrifugal forces, also explaining why the latter are referred to as "fictional forces". Cool example: when you're in a car going around a turn, squishing the person next to you, are you squishing him, or is he squishing you?