Unit 6

Today's lessons were really centered on Newton's second law of motion – force is equal to mass times acceleration, or "F=ma". This unit is structured around word problems, and many of them involve day-to-day situations such as acceleration of cars and elevators or pulleys. In class we did many activities and problems using pulleys. We learned that the larger the mass of the object attached to the pulley, the faster it will roll down when attached to a string. This got me thinking about free weights. I used to just think of weights as heavy objects to lift, but I never thought about the reasoning behind it. I realize now that the heavier the mass, the more Newtons of force you need to apply in order to overcome the weight force acting on the weight to the ground. Therefore each time you lift the weight, you need to apply more normal (applied) force than the weight force. Thinking about weights in a mathematical way helped me to understand why heavier weights were harder to lift.