Sunday 8 November 2015

How to measure variables for the new project

Recently in class, we started a project on investigating on improving our human body machines using our knowledge of work. We were to come up with a research question and think about the ways to prove it through measuring the change in the variables.

My research question is "How does the widths between the hands affect the amount of work performed while doing a pull-up?". The independent variable or the manipulated variable is the widths between the hands and the dependent or the response variable is the work performed while doing a pull-up. In this blog, I will be brainstorming ways to measure these variables.

*A pull-up in this context is an exercise involving one pulling himself up against a horizontal bar enough to touch his bottom of the chin on the top of the bar.



The widths between my hands can be measured with a ruler fairly accruately

To measure the work performed while doing  a pull-up, I must know the mass, acceleration, and the displacement since work = m x a x d.

             The mass that I pull during a pull-up is
              my total body weight - (weight of my hands+forearms)

            The acceleration is equal to the gravitational acceleration (9.81) since I am working against it.

            The distance over which I pull up myself can be measured with a ruler and is essentially the                 distance between the bottom of my chin and the bar when I am hanging with my arms                         straight on the bar.


I think I can measure these variables accurately through the ways mentioned above but if not I am considering making a model for better measurements.

Sunday 1 November 2015

This week we began the next unit. Unit 2.

How can we use our knowledge of physics to improve our human body machines?

Physics: Motion, Forces, Energy

WORK: MAD : Force * displacement (F*D)

We completed an exercise of finding the amount of work you perform if you jump one meter off the ground.
First we find the force which is:
F=m*a
F=!00 kg * 9.81 m/s
F= 981 N

Work= F*D
Work= 981 N * 1 meter= 981 J

J= Joules (unit for work)