Wednesday, January 28, 2015

Mass of Meter Stick


In class Monday we were assigned a meter stick with a weight strapped to the end. Every meter stick was a different weight and all we knew was the mass of the weight. The objective of the meter stick project was to find the weight of the meter stick just using the provided weight. Ali and I were grouped together and knew that the first peace of information to jot down was the center of gravity on the stick and the distance from the center of gravity and the end of the meter stick. This will be one of the lever arms. We can now find the torque, because torque= lever arm x force. The center of gravity was at 50 cm and the weight was 1 kg. To calculate force we multiply gravity by mass and we get .98. The meter stick with the weight balanced at 30 cm so the lever arm was 30 cm. Force .98 x Lever arm 20 cm, this will give you torque. And because the object is balanced  the torques on both sides must be equal. So .98 x 30 cm = the distance between the balancing point (50cm) and the center of gravity which was 20 cm. So .98 x 30 cm = 20 times lever arm (unknown x). When solving for x you get 1.47. So now you divide 1.47 by .98 and we got 145 grams. The actual weight measured on a scale was 150 grams. For future experiments to get more accurate results we could find a better table to measure the center of balance and more accurately measure center of gravity. This experiment  helped me by giving me a physical example of gravity and torque on objects. I know know how to use equations for torque to find the weight of objects.


Tuesday, January 20, 2015

Center Of Gravity



This video gives a blunt simple definition of center of gravity that is easy and understandable. The experiments they do are similar to one we has done in class they talk about how you must keep your weight over your center of gravity to keep balanced. They place emphasis on where your weight is distributed which is very important in understanding center of gravity, talk about staying low to keep your mass close to the center of gravity. Also its a sick cheesy physics video what could get better?

Torque



I like this video because it is short sweet an applicable. This video gives a simple yet in depth explanation of torque while giving everyday examples of how we see torque in everyday life. When turning a wrench the distance the shaft of the wrench is from the axis of rotation allows you to assert more force on the bolt. A lawn mover allows more rotational speed which allows it to cut through thicker grass. Torque is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist to an object. I no know what torque is all about and can recognize it wherever I go.