1.At least how many Calories does a mountain climber need to climb from sea leve
ID: 1361437 • Letter: 1
Question
1.At least how many Calories does a mountain climber need to climb from sea level to the top of a 4.22 km tall peak assuming the muscles of the climber can convert chemical energy to mechanical energy with an efficiency of 14.0 percent. The total mass of the climber and the equipment is 78.6 kg. (Enter your answer as a number without units.)
2. What is the specific heat of a substance if a 46.1-g sample increases in temperature by 18.0°C when it absorbs 790.0 J of heat?
The dimensions of specific heat are : energy/mass/temperature.(Temperature units can be expressed as either "K" or "degC")
Explanation / Answer
PE = mgh = 78.6*9.8*4220
PE =3.25 e 6 Joules of mechanical energy is needed
since efficiency is 14 percent
we need 3330353.6 * 0.14 Joules of chemical energy
e = 4.55 e 5 Joules
as 1 cal = 4.2 Joules
ans = 4.55 e 5 /4.2 = 1.08 e 5
-------------------------------------
use HEat Q = mc DT
specific heat c = Q/mDT
c = 790/(0.0461 * 18)
c = 952.036 J/kg degC
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.