Stair climbing has been shown to be an effective exercise that provides cardio and pulmonary benefits. It has made its w
Posted: Sat Jul 02, 2022 7:10 pm
Stair climbing has been shown to be an effective exercise thatprovides cardio and pulmonary benefits. It
has made its way into popular culture with exhortations to ‘takethe stairs instead of the elevator.’
For people with joint or skeletal issues such as arthritis,strains, etc. or for those recovering from
surgery, stair climbing may be recommended as a low-impactexercise choice. Note: It’s a low-impact exercise if one is walkingup the stairs and may be a low-impact exercise whenwalking down the stairs, if done thoughtfully.
People who require low-impact exercise should be particularlycareful while descending stairs. Although descending is not astaxing on the heart and lungs as going up, the extra drop with eachdown step can take a toll on the very body parts one is trying toprotect or rehabilitate, especially if the foot fall isuncontrolled/fast. The same is true of hiking in the mountains; thedescent may actually require greater care and mindfulness than theascent.
In terms of what you’ve learned about physics, why is a person’sfoot likely to be moving faster when it makes contact with a stepbelow as opposed to a step above? (Hint: Consider changes ingravitational potential energy, kinetic energy, and work doneagainst or with gravity.)
Also consider how the impact on a foot is related to impulse,average force, and duration studied in Chapter9: I = ∆p = pf – pi = Favg (∆t).If ∆t is the amount of time it takes for a foot to land on astep (from the moment of first contact to be fully supported bystep), how does slowing down or stepping mindfully reduce potentialinjury to the body... in terms of physics?
People with lower joint issues who have access to buildings withelevators sometimes elect to walk up the stairs and take theelevator down when exercising or going about their dailybusiness.
Running up and down stairs provides excellent cardio andpulmonary benefits, as well as some muscle strengthening in thelower body and core (abs/lower back) if proper posture ismaintained.
Researchers have even studied the benefits of climbing stairsone-at-a-time versus two-at-a-time. Taking two stairs at a timeincreases the rate of energy expenditure –i.e., power – but climbing stairs one-at-a- time resultsin more total energy used (i.e., Calories burned) if thenumber of stairs climbed is the same in each case.
Stair climbing has even become a competitive sport.See https://www.towerrunning.com/ for example. Elitestair runners have climbed 90 floors in about eightminutes. �
Step aerobics, which mimics the motion and benefits of stairclimbing, was invented as an alternative to traditional aerobicsclasses (think: leotards and leg warmers) as rehab for athleteswith knee injuries.
With many people avoiding gyms during the pandemic – or forscheduling, cultural, or personal reasons
-- stair climbing at home or outside can provide a useful,accessible, and safe alternative – as well as an excellent labactivity for understanding energy and power in physics class!
Items You’ll Need:
1. Access to some stairs or a staircase.2. Tape measure or ruler. (Nice if it’s marked in cm or meters, butyou’ve already demonstrated the ability
to convert American customary units to SI). 3. Calculator.
4. Stopwatch or watch that measures seconds. (Most phones have astopwatch feature; otherwise, a watch or clock with a second handwill work.)
5. Your mass, real or pretend, in kg.
Notes:Weight is a force vector measuredin Newtons and mass isa scalar quantity measured in kg. The unit for forcein American customary units is pound [lb], which I’m sure you’veheard of; the unit for mass in American customary units is the slugwhich you may not have heard of. Really, that’s what it is:slug.
2
1 Newton is the magnitude of force required to accelerate 1 kgof mass at 1 m/s . 2
Likewise, 1 lb is the magnitude of force required to accelerate1 slug of mass at the rate of 1 ft/s . In any equation, the numberson each side of the equal sign must match, as must the units (andthe directions if it’s a vector equation). So, it hurts physicsinstructors to see expressions like 1.0 kg = 2.2 lb written in manyplaces. This equation fails our standards for physics equationsbecause a mass is a fundamentally different physics quantity thanforce, so they can’t be equal!
However... on the surface of the Earth, it is true that 1 kg ofmass has a weight of 9.8 N due to the local acceleration ofgravity, g = 9.8 m/s . It is also true that 1.00 N = 0.225 lband
0.225 𝑙𝑙𝑙𝑙 2 9.8 N x 1.00 𝑁𝑁 = 2.2 lb.
Therefore – on the surface of the Earth! – a mass of 1kg will have a weight of 2.2 lb. As long as you understand thatcaveat, your physics instructor will be able to sleep at night(after the 4-1/2 week course, 4-credit course �).
So you may use the above as a shortcut for this lab activity, aslong as the stairs you’re using are on or near the surface of theEarth. [You are not obliged to disclose personal info just to learnfrom this activity, so go ahead and use a different yetrealistic-for-humans mass if you wish.]
Procedure:
Determine the vertical height of the set of stairs you plan toclimb.
The vertical height refers to the height from the bottom to thetop (straight up and down) and is not the diagonaldistance along the slope of the stairs.
As this can often be difficult to measure directly, think abouthow you could determine this vertical height from measurements thatare easier to take accurately. Explain your method, include adiagram or sketch as appropriate, and show your work/calculations.[What is obvious to you in the moment may not be obvious to areader of your notes, or to you a year from now. Use these asstandards for how much to sketch and record about your technique:Could a reader – or you, a year from now -- recreate yourexperimental work just from your lab notes?]
Decide whether you’re going to walk or run, and note that.
Use the stopwatch, watch, or clock to time the number of secondsit takes you to walk or run up the stairs. Record yourmeasurement.
Repeat #3 two more times, recording your data each time. Whenrecording measurements and outcomes of calculations, always includethe appropriate unit with each number. Take the time to create asimple data table with well-labeled columns.
Take a selfie of you and the stairs you used, and put it in yourlab report.
6. Find the average of your three measurements. Why do you thinkyou were asked to do it and measure it more than once?
Note: Taking data multiple times is an important aspect of allscience experiments.
A systematic error is one that creates a tendency forthe data to be inaccurately skewed in a particular direction.Systematic errors are different from random errors thatare created by natural variations or limitations in the experimentor measurements.
Note that scientists and mathematicians use the term “error”even when they aren’t referring to actual mistakes. Many of uswould better recognize these ideas as systematic or random“uncertainties.”
Think about and note one or two possible sourcesof systematic errors in this activity.
Think about and note one or two possible sourcesof random errors in this activity.
Analysis:
Determine the amount of physics work you’ve doneduring each climb. Explain your work. Carry units appropriately.Add this as a column in your table.
Determine the average power you exerted during eachclimb. Explain your work. Carry units appropriately. Add this as acolumn in your table.
Do you notice any trend in your results? If so, describe. Ifnot, briefly explain why there’s no evidence for a trend.
What is the average work and the average power from your threeclimbs?
Using the appropriate average from #10, determine how manyCalories1 you expended. 1 Joule = 0.00024 Calories
Is this number more or less than you expected?
1You may have already seen calories described in other sciencecourses, particularly chemistry. One calorie – note thelower-case c at the beginning – is the amount ofthermal/heat energy needed to raise the temperature of 1 gram ofwater by 1°C. This lower-case-c calorie is equal to 4.2 Joules.However (!), the Calories – note the upper-case C –reported on food packages are actually kilocalories and are 1,000times greater than the lower-case-c calories. In Europe, foodpackages are labeled in kcal (kilocalories) which clarifies theissue. In the U.S., however, the lower-case-c and upper-case-Cconvention is not always followed so one needs to pay attention tocontext. For example, are you in a chemistry lab (calorie) or areyou reading a cereal box at the grocery store (Calorie)?
Now compare your power to that of a typical 10-Watt LED lightbulb. (Note that this is far less than traditional light bulbswhich typically consumed 60-100 Joules of energy per second.) Usingthe data and information you have, report how many 10-Watt LEDlight bulbs you could power with your stair climbing. Show yourwork.
has made its way into popular culture with exhortations to ‘takethe stairs instead of the elevator.’
For people with joint or skeletal issues such as arthritis,strains, etc. or for those recovering from
surgery, stair climbing may be recommended as a low-impactexercise choice. Note: It’s a low-impact exercise if one is walkingup the stairs and may be a low-impact exercise whenwalking down the stairs, if done thoughtfully.
People who require low-impact exercise should be particularlycareful while descending stairs. Although descending is not astaxing on the heart and lungs as going up, the extra drop with eachdown step can take a toll on the very body parts one is trying toprotect or rehabilitate, especially if the foot fall isuncontrolled/fast. The same is true of hiking in the mountains; thedescent may actually require greater care and mindfulness than theascent.
In terms of what you’ve learned about physics, why is a person’sfoot likely to be moving faster when it makes contact with a stepbelow as opposed to a step above? (Hint: Consider changes ingravitational potential energy, kinetic energy, and work doneagainst or with gravity.)
Also consider how the impact on a foot is related to impulse,average force, and duration studied in Chapter9: I = ∆p = pf – pi = Favg (∆t).If ∆t is the amount of time it takes for a foot to land on astep (from the moment of first contact to be fully supported bystep), how does slowing down or stepping mindfully reduce potentialinjury to the body... in terms of physics?
People with lower joint issues who have access to buildings withelevators sometimes elect to walk up the stairs and take theelevator down when exercising or going about their dailybusiness.
Running up and down stairs provides excellent cardio andpulmonary benefits, as well as some muscle strengthening in thelower body and core (abs/lower back) if proper posture ismaintained.
Researchers have even studied the benefits of climbing stairsone-at-a-time versus two-at-a-time. Taking two stairs at a timeincreases the rate of energy expenditure –i.e., power – but climbing stairs one-at-a- time resultsin more total energy used (i.e., Calories burned) if thenumber of stairs climbed is the same in each case.
Stair climbing has even become a competitive sport.See https://www.towerrunning.com/ for example. Elitestair runners have climbed 90 floors in about eightminutes. �
Step aerobics, which mimics the motion and benefits of stairclimbing, was invented as an alternative to traditional aerobicsclasses (think: leotards and leg warmers) as rehab for athleteswith knee injuries.
With many people avoiding gyms during the pandemic – or forscheduling, cultural, or personal reasons
-- stair climbing at home or outside can provide a useful,accessible, and safe alternative – as well as an excellent labactivity for understanding energy and power in physics class!
Items You’ll Need:
1. Access to some stairs or a staircase.2. Tape measure or ruler. (Nice if it’s marked in cm or meters, butyou’ve already demonstrated the ability
to convert American customary units to SI). 3. Calculator.
4. Stopwatch or watch that measures seconds. (Most phones have astopwatch feature; otherwise, a watch or clock with a second handwill work.)
5. Your mass, real or pretend, in kg.
Notes:Weight is a force vector measuredin Newtons and mass isa scalar quantity measured in kg. The unit for forcein American customary units is pound [lb], which I’m sure you’veheard of; the unit for mass in American customary units is the slugwhich you may not have heard of. Really, that’s what it is:slug.
21 Newton is the magnitude of force required to accelerate 1 kgof mass at 1 m/s . 2
Likewise, 1 lb is the magnitude of force required to accelerate1 slug of mass at the rate of 1 ft/s . In any equation, the numberson each side of the equal sign must match, as must the units (andthe directions if it’s a vector equation). So, it hurts physicsinstructors to see expressions like 1.0 kg = 2.2 lb written in manyplaces. This equation fails our standards for physics equationsbecause a mass is a fundamentally different physics quantity thanforce, so they can’t be equal!
However... on the surface of the Earth, it is true that 1 kg ofmass has a weight of 9.8 N due to the local acceleration ofgravity, g = 9.8 m/s . It is also true that 1.00 N = 0.225 lband
0.225 𝑙𝑙𝑙𝑙 2 9.8 N x 1.00 𝑁𝑁 = 2.2 lb.
Therefore – on the surface of the Earth! – a mass of 1kg will have a weight of 2.2 lb. As long as you understand thatcaveat, your physics instructor will be able to sleep at night(after the 4-1/2 week course, 4-credit course �).
So you may use the above as a shortcut for this lab activity, aslong as the stairs you’re using are on or near the surface of theEarth. [You are not obliged to disclose personal info just to learnfrom this activity, so go ahead and use a different yetrealistic-for-humans mass if you wish.]
Procedure:
Determine the vertical height of the set of stairs you plan toclimb.
The vertical height refers to the height from the bottom to thetop (straight up and down) and is not the diagonaldistance along the slope of the stairs.
As this can often be difficult to measure directly, think abouthow you could determine this vertical height from measurements thatare easier to take accurately. Explain your method, include adiagram or sketch as appropriate, and show your work/calculations.[What is obvious to you in the moment may not be obvious to areader of your notes, or to you a year from now. Use these asstandards for how much to sketch and record about your technique:Could a reader – or you, a year from now -- recreate yourexperimental work just from your lab notes?]
Decide whether you’re going to walk or run, and note that.
Use the stopwatch, watch, or clock to time the number of secondsit takes you to walk or run up the stairs. Record yourmeasurement.
Repeat #3 two more times, recording your data each time. Whenrecording measurements and outcomes of calculations, always includethe appropriate unit with each number. Take the time to create asimple data table with well-labeled columns.
Take a selfie of you and the stairs you used, and put it in yourlab report.
6. Find the average of your three measurements. Why do you thinkyou were asked to do it and measure it more than once?
Note: Taking data multiple times is an important aspect of allscience experiments.
A systematic error is one that creates a tendency forthe data to be inaccurately skewed in a particular direction.Systematic errors are different from random errors thatare created by natural variations or limitations in the experimentor measurements.
Note that scientists and mathematicians use the term “error”even when they aren’t referring to actual mistakes. Many of uswould better recognize these ideas as systematic or random“uncertainties.”
Think about and note one or two possible sourcesof systematic errors in this activity.
Think about and note one or two possible sourcesof random errors in this activity.
Analysis:
Determine the amount of physics work you’ve doneduring each climb. Explain your work. Carry units appropriately.Add this as a column in your table.
Determine the average power you exerted during eachclimb. Explain your work. Carry units appropriately. Add this as acolumn in your table.
Do you notice any trend in your results? If so, describe. Ifnot, briefly explain why there’s no evidence for a trend.
What is the average work and the average power from your threeclimbs?
Using the appropriate average from #10, determine how manyCalories1 you expended. 1 Joule = 0.00024 Calories
Is this number more or less than you expected?
1You may have already seen calories described in other sciencecourses, particularly chemistry. One calorie – note thelower-case c at the beginning – is the amount ofthermal/heat energy needed to raise the temperature of 1 gram ofwater by 1°C. This lower-case-c calorie is equal to 4.2 Joules.However (!), the Calories – note the upper-case C –reported on food packages are actually kilocalories and are 1,000times greater than the lower-case-c calories. In Europe, foodpackages are labeled in kcal (kilocalories) which clarifies theissue. In the U.S., however, the lower-case-c and upper-case-Cconvention is not always followed so one needs to pay attention tocontext. For example, are you in a chemistry lab (calorie) or areyou reading a cereal box at the grocery store (Calorie)?
Now compare your power to that of a typical 10-Watt LED lightbulb. (Note that this is far less than traditional light bulbswhich typically consumed 60-100 Joules of energy per second.) Usingthe data and information you have, report how many 10-Watt LEDlight bulbs you could power with your stair climbing. Show yourwork.