If you saw our previous video this week, you got a good introduction to Projectile Motion. Today's free Physics 1 video is about Understanding Projectile Motion. We already saw the six one-dimensional equations for solving any problem that you want with constant acceleration, and in particular, any free-fall problem. We learned that projectile motion is free-fall in two dimensions and that the beauty of projectile motion is that motion in the x-direction is independent of motion in the y-direction. Professor Pollock continues running through examples to help you understand how to calculate different aspects of projectile motion, whether it's velocity, time or range. It can be frustrating trying to figure out which of the six one-dimensional equations to use in order to solve projectile motion questions. Often you'll need to use more than one, but the examples on the video help solidify the way to determine which equations will get you to the correct answer.

# January 2011 Archives

Today's free Physics 1 video is A First Look at Projectile Motion. Unlike the previous videos we've published on describing motion, we're now looking at motion in two dimensions. When discussion projectile motion, free fall is an important concept to understand. Free fall means the only force acting on you is gravity. When you think of a projectile you have the outward motion but you also have gravity pulling the object to the ground. Luckily, the master equations of kinematics for constant acceleration can be used to describe free fall in two dimensions. Professor Pollock will share these equations and show how they tell you everything about the path and motion of a projectile. With the help of Professor Fischbach, they also demonstrate what happens if two objects are simultaneously dropped to the ground when one of the objects has horizontal velocity. The result is not what you would intuitively expect!

We thought we would try something a little different today. We're doing a blog exchange with University Bound, a site dedicated to providing
potential online students with the information that they need to make
informed, responsible educational decisions. If you are curious about what we wrote, check out our blog post here.

These days, a walk through a modern classroom might find students and teachers focused on the Smartboard in front of the classroom, students leaning over their computers as teachers instruct algebra, or they could have the latest iPad in hand with current science news streaming live. This kind of technology is not just in the K-12 classroom, either. With every year, more adults are using online classrooms to get a degree or earn an additional higher one. These are only a few ways in which multimedia have changed the traditional classroom dynamic, in K-12 and higher education schools. Nowadays, with younger people using technology earlier, teachers are keeping pace by instituting teaching methods that use these technologies. As technology continues to improve every year, and as more businesses use it for employee training and ways of operating, it is becoming increasingly beneficial for children and adults to learn to harness these technologies.

Multimedia can come in many shapes and forms. In the K-12 classrooms, you could see students using iPads, iPod Touches and other computer technologies. Teachers use Smartboards, high-tech computer software and programs, and information sharing programs like Wiki and Blackboard. Students and teachers are connecting more than ever on social media sites like Facebook and Twitter. Students can get up-to-date information for their class online, while teachers can collaborate on effective teaching skills or ideas. The younger a student learns to effectively and productively use tools and platforms like these, the more able they are to function competitively in an increasingly tech-driven world.

As well as K-12 students and teachers, those in higher and online education have found that multimedia use in the classroom to be extremely beneficial. Scientific journals and reports and current events accessed online, and interactive software and information sharing sites have become the norm in the college classroom. It is the exclusive norm in an online college classroom - lectures and assignments are viewed and completed online as part of the curriculum.

Below are a few reasons why students and teachers alike are embracing multimedia in the classroom:

- Learning is more interactive and engaging for both.
- With more visual aids and interactive materials, students are more likely to retain and understand challenging concepts.
- New scientific discoveries and current events are only a click away, which makes classroom learning always up-to-date and relevant in today's world.
- More collaborative learning between the students and between the teachers.
- Access to global classrooms enables students from other countries to learn from each other.

Multimedia use in the classroom is quickly replacing traditional teaching methods. As we continue to move toward the goal of having all classrooms and schools outfitted with this technology, the end result is certainly a more learned and tolerant populace - one that will collaborate on new ideas, one that will advance education even more for their children, and one that will connect with people across the globe more than ever before.

Still in its infancy stages, the modern classroom will always rely on traditional methods of teaching. Teachers, no matter if they are right in front of you or on the computer screen, will still be highly respected and educated individuals that are relied upon to learn, understand, and subsequently break down lessons into digestible learning segments for their students. Students will still have to collaborate with each other and learn from their mistakes, despite advances in technology that may enable them to bypass these important learning steps. Even in higher education, whether online or traditional, students are still expected to use their own cognitive and conversational skills in order to successfully pass a class. As the poet John Donne said about the human condition, "No man is an island", the same can be said about the ever-expanding global classroom.

With all the discussion of motion in the past few physics videos, it's time for one of my favorite times in science class: lab time! So today's free Physics 1 video is a Physics in Action demonstration on The Three Balls Demo. This demonstration involves uniform circular motion, where three balls are attached to a disk by string and then spun. Since the balls are in uniform circular motion, the direction of the instantaneous velocity vector is tangent to the circle and because of this what happens when the strings are cut is very interesting. Don't want to spoil what happens, but needless to say this is a great example of Newton's first law in effect.

We've been learning about kinematics with the past few physics videos. But, what if instead of describing how things move, we want to learn why they move they way they do? That's where we start looking at dynamics. Dynamics is the description of motion and the forces that cause it. While Galileo initially started the process of thinking about motion, Isaac Newton really was the first to understand the prime ideas of dynamics. It's because of this understanding that he was able to develop his ideas into what are now considered laws of motion. In today's free Physics 1 video, we're going to learn about Newton's First Law. Many of you have heard it before. An object at rest remains at rest and an object in motion stays in motion unless acted upon by an external unbalanced force. A force is nothing more than a push or a pull and what Newton's First Law is telling us is if you don't push on something, then it's not going to change its motion. Check out today's video to learn more and see some examples of Newton's Law in action.

Say you are standing on the sidewalk and you look up to see a piano and a book falling. Which one is going to hit the ground first? Instinct tells us the piano would fall to the ground first because it is the heaviest, but surprisingly, that's just not true. Both objects will fall to the ground at the same time. Objects do not fall with uniform velocity; instead they fall with uniform acceleration. Free-fall acceleration occurs when an object is subject only to the force of gravity. This is something Galileo first experimented with when he dropped objects from the top of the Leaning Tower of Pisa. In today's free Physics 1 video, you'll learn about the reality of Free-Falling Objects. Today's lecture even includes a great demo on air friction's impact on free-falling and a great example of how this knowledge can be used in the real world.

Today we continue describing motion by talking about acceleration. Acceleration is the rate of change of velocity over time. We most often think of acceleration when thinking of cars and how fast they can go. However, acceleration can be slowing down in addition to speeding up as it's about the rate of change and not the direction of movement. Velocity is not as important as the change in velocity per unit time, which is known as average acceleration. Why is the change more important than velocity? Think of this, you are in a car going 60 mph and it changes to 0 mph in 1 second. As Professor Steven Pollock notes in his lecture, this would most likely mean you were in a wreck and that could really matter if you were in the car! Of course, this is all describing constant acceleration, which is simple to calculate because no matter if you are slowing down or speeding up it's in a straight line fashion. However, sometimes acceleration is not at a constant speed and in today's free Physics 1 video on Acceleration, you'll learn how to calculate this. Next time you get in a car, think about acceleration and you'll see the trip in a whole new light!

Kinematics is a branch of mechanics that deals with the description of motion. It comes from the Greek word "kinema", meaning to move. The simplest kind of motion to describe is motion in one dimension. One dimension refers to movement that is in a line. It can be backward and forward or up and down but not both. In order to describe motion in one dimension, you need to know the variables of time and position. Time is easily measured with a stopwatch, but the number used to describe position is based on an arbitrary coordinate system, while the position itself is real. These basics are important as they are the foundation for the more complicated physics concepts that will come later. In today's free Physics 1 video on Describing Motion with Professor Steve Pollock, you'll learn all about kinematics and see examples of how you can graph and describe motion. It's a good place to start thinking about motion and physics.

When it comes to the shapes you learn about in Geometry, the circle can be the trickiest. You don't have all those nice straight lines to work with and instead have curves, a whole different set of formulas, and pi. We saw some of these differences at work on the video on Spheres.

Measuring the side of a square is one thing but what do you do when you want to measure the length of an arc? An arc of a circle is basically any connected part of the circle's circumference and finding the measurement of an arc is directly related to the measurement of the central angle for that arc. In today's free Geometry video on Arcs and Chords, you'll learn how to calculate the measurement of both an arc and a chord. A chord is a line segment whose endpoints lie on the circumference of the circle. The four lectures on the video will give you a great understanding of Arcs and Chords. Just be sure to click the forward button the left of the time stamp to move to the next lecture on the video.

Many people don't understand why a school would have teachers use our videos instead of simply teaching the course themselves. Thankfully, eSchoolNews published an article this past week that explained exactly this concept. See, when it comes to public education, Thinkwell has been a champion of what is called the inverted classroom model, and in fact, our courses are often used for this purpose. The thinking behind this is that instructors have students watch our lectures as homework and then spend their classroom time engaging their students. Class time becomes more about targeting the information that students are challenged with or allowing for group work or activities to reinforce the knowledge. It's one of those ideas that when you hear it, it just makes sense. I particularly appreciated the article in eSchoolNews because they took the time to interview teachers using this model and showed how it is helping students succeed in otherwise difficult classes. When you think about how little time a teacher has in an hour-long class, it clicks that this model encourages true learning. It enables students to work through the curriculum at their own pace, which can be very helpful when you have students who need one-on-one attention. Having the lectures online and easily accessible also allows students who don't need help the opportunity to access future lectures instead of sitting in the classroom bored.

It seems to me this is an excellent idea that would make classrooms more efficient and allow teachers to target a wide variety of learning styles. What do you think about the inverted learning model? Do you believe this could be a positive direction for schools?