In fact, if one remembers to use the parallel axis theorem, it is even easier. Let's start with a simple yo-yo motion - here, the stringless yo-yo works pretty much the same as a traditional one, you just need to tug on the string to create friction and send the toy travelling upwards again before you run out of fabric. Physics teachers spend their days showing and explaining the marvels of physics, which underlies all the other science subjects, including biology, chemistry, Earth and space science. How do I get the acceleration down the inclined plane? Objective To investigate how string length affects yo-yo sleep time. What is the coefficient of static friction? Why does a spinning yo-yo feel weird in your hand? And actually when you think about playing with a Yo-Yo, part of the fun is that you can keep it going — up and down and up and down — over and over again because it is unraveling down, but then re-wrapping the string around the axle on the way up. Yo-Yos by John, Kevin and Minna. When you release a yo-yo, gravity acts on its center of mass to pull the yo-yo downward.
When the yo-yo is being held it has the potential to fall and spin. The miniature box was hand-painted with an image depicting a girl playing with her yo-yo. Because the string of the yo-yo is wrapped around the yo-yo's axle, and because one end of the string is attached to your finger, the yo-yo is forced to rotate as it drops. Instead of being slowed by frictional force I; the yo-yo is slowed by the force f on it from the string. Also because I know that the equation for potential energy due to gravity is always mgh and the kinetic energy equation always has to do with a squared velocity, my guess is a square root of some ratio between gravity, height, and the geometry of the Yo-Yo. If you know the radius of the axle, and you give the yo-yo an initial velocity downward, you can determine the rate of rotation in terms of the velocity and the radius. Hence it is rare for the string to slip after that process has begun.
If an object is in free fall, the only force acting upon it is gravity. Make the yo-yo spin faster, however, and the weights fly out from the axle because of centrifugal force or, if you prefer, because the springs cannot provide enough centripetal force to keep them in. As a yo-yo climbs up and down its string, it is constantly exchanging potential and kinetic energy—much like a car. As it climbs back up, it loses kinetic energy and regains potential energy. His research interests include making polarized gas and using neutrons to examine magnetic materials and the decay of neutrons. The glue made it rather difficult to open one up. If something is done to prevent the string from freely spinning then the energy that was driving the YoYo to rotate in place is now used to reel in the string.
But a yo-yo is different from a stone because it has string wrapped around its. The main objective of performing this experiment is to measure the velocity and position of the ball to eventually find the acceleration of free fall. YoYo Problem In class I did the yoyo calculation choosing the torque point at the spool center of mass. Why do you think so? Linear momentum is momentum in a straight line and is present when the yo-yo is falling. Her body compensates for this by changing her velocity to keep her angular momentum constant.
There's a lot of physics going on in your yo-yo. The Yo-Yo is released from rest. There's a lot of science history here as well as a basic introduction to forces and motion. Cut the yo-yo string to the length you measured with the yardstick. To reach that goal, they observe and measure natural events seen on Earth and in the universe, and then develop theories, using mathematics, to explain why those phenomena occur.
Aerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a solid object. Plot your data on a scatter plot so that you can show your results to other people. As the string unwinds, it generates torque on the axle and this torque is responsible for the yo-yo's angular momentum. So far so good, but how does a tiny, light piece of string catch and stop a solid plastic yo-yo mid-air? That's one reason why you can do all kinds of neat tricks with it! So now going back to compare this answer to my guess which was 2mg I see how wrong I was with my initial intuition. Eventually, the yo-yo comes to rest at the bottom. Because the full length of the string has been paid out, the yo-yo can drop no further and, consequently, the rotation rate cannot increase further.
Introduction Most people are familiar with the yo-yo as a fun and cool toy. Label the x-axis String length and the y-axis Sleep time. The figure on the left shows the relatively simple construction: just as in a modern yo-yo, the two outer discs have a space between them held together by a rivet green around which the string wraps. That's because she changes the way her mass is distributed. Or just watch the video again to enjoy the the art of physics in action. For any other use, please contact Science Buddies.
This gives us equation 4 , and we now have 4 equations and 4 unknowns. This is the same effect that causes footballs, bullets, and the earth to stay pointed in the same direction. I recall that the wax was a bit tacky if you put it on a cold surface and touched it, but it would get very slippery when you rubbed it or it got a bit warm. Once winding begins frictional forces between the string and barrel increase with more string in close contact with the barrel and wound string overlaying earlier wound layers. This may seem like magic, but it's actually just physics at work. A force of 175N needed to keep a 640N engine from sliding. When you flick your wrist, the tension on the string is removed and the friction of the metal shaft is sufficient to wind the string.
For the yo-yo, less of the potential energy would be converted into kinetic energy because some of the potential energy would be used in spinning the yo-yo some of the potential energy would be converted into angular momentum. It is the second oldest toy, after dolls. Now I was actually pretty close on my guess here. You can also take a look at books about yo-yos to learn how to yo-yo. In energy State 1, like we said earlier, both the linear and angular velocity is zero, so we have no kinetic energy. Like an ice skater, it tries to keep its angular momentum constant or, as physicists say, to conserve its angular momentum. However, a momentary tug on the string causes the friction between the string and the axle briefly to increase so that the axle no longer slips within the string.