In this video I illustrate a simple acceleration force by dragging my ipod across the floor, slowly at first, but then faster and faster to demonstrate how it changes speed. Obviously, my ipod represens the object. At first it's at rest - and at no time during the motion does it leave the ground; this means that two of the forces at work are the ipod pushing down with "weight" onto the Earth, and the Earth pushing up on the ipod with equal magnitude with "normal" force. The earphones inside the ipod are the force specifically pulling my ipod (obviously because I'm pulling it... but for the sake of the video, work with me here). The chord represents the unbalanced force of "pulling" to the left. The only force opposite this pulling is the friction of the floor, because it's rigid; however the pulling force is greater than the friction force thus leaving the equation unbalanced and the object to accelerate. Below is a more literal illustration of this motion.
Notice that the arrows of force in the up and down direction are equal magnitude, which is there is no acceleration in the y axis. However, the arrow for the pulling force arrow has much more magnitude than the smaller friction arrow in the opposite direction. It's not balanced, thus the acceleration on the x axis in the positive direction is justified.
boy you're quick! i hope your ipod didnt get scratches...nice diagram explanation of the video
ReplyDeleteHmm, I might question some of your ideas, pal.
ReplyDeleteFirst off, you said that the force to the right of the ipod was a "Force: Pulling" force. However, you're pulling it by the earphone chord - that's called "tension".
In other words, I think you only use "pushing/pulling" if an object (such as your hand) is directly touching the object you're moving. If the chord is pulling the iPod, I think it's tension.
Also, you said that as you pull the iPod, the velocity gets faster and faster - constantly accelerating. I have to argue against that.
Constantly accelerating means that an object is constantly getting faster and faster. This is very hard to do in a short distance and with little force. I think what actually happened was that you started off by accelerating, but then your object quickly went back to traveling at a constant velocity.
In other words, I think it only accelerated for about a second, since accelerating for like 5 seconds or more would have you chasing after your iPod in a sprint!
Thank you Sandra!
ReplyDeleteAnd Sean, I'm lazy, soooooo yeah. But thanks for the helpful input : )