Phys151 Engineering Physics 2025
Tutorial on Temperature and Heat
1) On January 22, 1943, the temperature in Spearfish, South Dakota, rose from −4.0°F to
45.0°Fin just 2 minutes.
(a)What was the temperature change in Celsius degrees?
(b)The temperature in Browning, Montana, was 44.0°F on January 23, 1916. The next
day the temperature plummeted to −56°F. What was the temperature change in Celsius
degrees?
2) The pressure of a gas at the triple point of water is 1.35 atm. If its volume remains
unchanged, what will its pressure be at the temperature at which CO2 solidifies?
3) The outer diameter of a glass jar and the inner diameter of its iron lid are both 725 mm
at room temperature 20.0°C. What will be the size of the difference in these diameters
if the lid is briefly held under hot water until its temperature rises to 50.0 °C without
changing the temperature of the glass?
4) In very cold weather a significant mechanism for heat loss by the human body is energy
expended in warming the air taken into the lungs with each breath.
(a) On a cold winter day when the temperature is −20.0°C, what amount of heat is
needed to warm to body temperature (37°C) the 0.50 L of air exchanged with each
breath? Assume that the specific heat of air is 1020 J/kg. K and that 1.0 L of air has
mass 1.3 × 10−3 kg.
(b) How much heat is lost per hour if the respiration rate is 20 breaths per minute?
5) You have 750 g of water at 10.0°C in a large insulated beaker. How much boiling water
at 100.0°C must you add to this beaker so that the final temperature of the mixture will
be 75°C?
6) An open container holds 0.550 kg of ice at −15.0°C. The mass of the container can be
ignored. Heat is supplied to the container at the constant rate of 800.0 J/min for
500.0 min.
(a)After how many minutes does the ice start to melt?
(b)After how many minutes, from the time when the heating is first started, does the
temperature begin to rise above 0.00°C?
