40 Questions
What is the concept of energy that remains fixed in any process that occurs in nature?
Conservation of energy
What is the symbol for the stored energy in the body?
ΔU
What happens to a body that is doing no work and at a constant temperature?
It loses heat to the surrounding environment
What is the rate of doing work in the body?
P
What is the equation that relates the change in stored energy, heat lost, and work done by the body?
ΔU = ΔQ - ΔW
What is the unit of Δt?
Seconds
What is the measure of the human body's ability to do work?
Energy
What unit is used to express food energy?
Kilocalories
What is the unit of energy in the SI system?
Joule
What is the unit of power in the SI system?
Watt
What is the unit of expressing the rate of energy consumption of the body?
Metabolic Equivalents
What is the conversion of 1 erg in Joule?
1 erg = 10^(-7) J
What happens when your body's internal energy is lost in a short time interval?
You tend to feel tired
Why does cycling require less energy than running?
Because cycling has less gravitational potential energy to overcome
What is the purpose of sweating when your body does much work?
To lose excess heat
What provides the energy necessary for muscle contraction?
The energy released by chemical reactions
What happens to the body's internal energy when you consume food?
It increases
What is the result of the energy released by chemical reactions in the body?
Both work and heat are generated
What is the primary reason why your bike would gradually slow down if you did not pedal at all?
Because of the friction
What happens to the kinetic energy of a runner when their body moves downward?
It decreases
What is the characteristic of more efficient runners?
They bob up and down less
Why does a runner's center of mass continually alternate between speeding up and slowing down?
Because of the stride motion
What happens to the gravitational potential energy of a runner when they move upward?
It increases
What is the main difference between riding a bike and running on a flat surface?
The constancy of kinetic energy
What is the primary purpose of the body's temperature regulation mechanisms?
To maintain a constant body temperature despite environmental fluctuations
What type of radiation does the body emit?
Electromagnetic radiation
What is the approximate value of the radiation coefficient (𝐾𝐾𝑟𝑟)?
5 kcal/m2.hr.˚C
What is the formula for heat loss due to radiation (𝐻𝐻𝑟𝑟)?
𝐻𝐻𝑟𝑟 = 𝐴𝐴𝑟𝑟 × 𝐾𝐾𝑟𝑟 × (𝑇𝑇𝑠𝑠 - 𝑇𝑇𝑤𝑤)
What is the primary factor that affects the convection coefficient (𝐾𝐾𝑐𝑐)?
Movement of the air
What is the heat loss due to convection (𝐻𝐻𝑐𝑐) proportional to?
The difference between the skin temperature and the wall surrounding temperature
Muscles consist of bundles of protein filaments.
False
When a muscle contracts, it generates a force that acts through a distance.
True
The energy used by the body when muscles contract is always in the form of kinetic energy.
False
The work done by the biceps muscle is equal to the work done by the force the hand exerts on the weight.
True
The heat generated by the body when muscles contract is always equal to the work done by the muscles.
False
When you hold a weight in your hand and contract the biceps muscle in your arm, the weight's gravitational potential energy decreases.
False
Muscles can only contract in one direction.
False
The energy used by the body when muscles contract is always used to move one of the body's limbs.
False
Muscles can convert all the energy they use into work.
False
The work done by muscles is always proportional to the force they exert.
False
Understand the concept of energy, its conservation in the human body, and how it relates to work and power. Learn about the different forms of energy, including mechanical, electrical, chemical, nuclear, and thermal energy. Assess your knowledge of energy conversion, work done, and power exerted by the human body.
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