Food calories. The food calorie, equal to 4186 J, is a measure of how much energy is released when food is metabolized by the body. A certain brand of fruit-and-cereal bar contains 140 food calories per bar. (a) If a 65 kg hiker eats one of these bars, how high a mountain must he climb to “work off” the calories, assuming that all the food energy goes only into increasing gravitational potential energy? (b) If, as is typical, only 20% of the food calories go into mechanical energy, what would be the answer to part (a)? (Note: In this and all other problems, we are assuming that 100% of the food calories that are eaten are absorbed and used by the body. This is actually not true. A person’s “ metabolic efficiency ” is the percentage of calories eaten that are actually used; the rest are eliminated by the body. Metabolic efficiency varies considerably from person to person.)
Food calories. The food calorie, equal to 4186 J, is a measure of how much energy is released when food is metabolized by the body. A certain brand of fruit-and-cereal bar contains 140 food calories per bar. (a) If a 65 kg hiker eats one of these bars, how high a mountain must he climb to “work off” the calories, assuming that all the food energy goes only into increasing gravitational potential energy? (b) If, as is typical, only 20% of the food calories go into mechanical energy, what would be the answer to part (a)? (Note: In this and all other problems, we are assuming that 100% of the food calories that are eaten are absorbed and used by the body. This is actually not true. A person’s “ metabolic efficiency ” is the percentage of calories eaten that are actually used; the rest are eliminated by the body. Metabolic efficiency varies considerably from person to person.)
Food calories. The food calorie, equal to 4186 J, is a measure of how much energy is released when food is metabolized by the body. A certain brand of fruit-and-cereal bar contains 140 food calories per bar. (a) If a 65 kg hiker eats one of these bars, how high a mountain must he climb to “work off” the calories, assuming that all the food energy goes only into increasing gravitational potential energy? (b) If, as is typical, only 20% of the food calories go into mechanical energy, what would be the answer to part (a)? (Note: In this and all other problems, we are assuming that 100% of the food calories that are eaten are absorbed and used by the body. This is actually not true. A person’s “metabolic efficiency” is the percentage of calories eaten that are actually used; the rest are eliminated by the body. Metabolic efficiency varies considerably from person to person.)
Chemical pathways by which living things function, especially those that provide cellular energy, such as the transformation of energy from food into the energy of ATP. Metabolism also focuses on chemical pathways involving the synthesis of new biomolecules and the elimination of waste.
Current Attempt in Progress
In the figure what is the net electric potential at point P due to the four particles if V = 0 at infinity, q = 2.12 fC, and d = 1.75 cm?
d
Number
MI
Units
+q
Current Attempt in Progress
In the figure what is the net electric potential at point P due to the four particles if V = 0 at infinity, q = 2.12 fC, and d = 1.75 cm?
d
Number
MI
Units
+q
A 0.500 kg sphere moving with a velocity given by (2.00î – 2.60ĵ + 1.00k) m/s strikes another sphere of mass 1.50 kg moving with an initial velocity of (−1.00î + 2.00ĵ – 3.20k) m/s.
(a) The velocity of the 0.500 kg sphere after the collision is (-0.90î + 3.00ĵ − 8.00k) m/s. Find the final velocity of the 1.50 kg sphere.
R =
m/s
Identify the kind of collision (elastic, inelastic, or perfectly inelastic).
○ elastic
O inelastic
O perfectly inelastic
(b) Now assume the velocity of the 0.500 kg sphere after the collision is (-0.250 + 0.850ĵ - 2.15k) m/s. Find the final velocity of the 1.50 kg sphere.
✓ =
m/s
Identify the kind of collision.
O elastic
O inelastic
O perfectly inelastic
(c) Take the velocity of the 0.500 kg sphere after the collision as (−1.00ỉ + 3.40] + ak) m/s. Find the value of a and the velocity of the 1.50 kg sphere after an elastic collision. (Two values of a are possible, a positive value and a negative value. Report each with their
corresponding final velocities.)
a…
Applications and Investigations in Earth Science (9th Edition)
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