Final Exam in MATH 223 - Part 1

Find the velocity of escape of the Apollo spaceship as it is projected from the earth surface, that is the minimum velocity imparted to it so that it wil never return. The radius of the earth is 4000 miles and the acceleration of the spaceship is 32.2 ft/s.

• 40,465 kph
• 44,605 kph
• 56,440 kph
• 60,544 kph

At 9 a.m., a thermometer reading 70°F is taken outside where the temperature is 15°F. At 9:05 a.m, the thermometer reading is at 45°F. At 9:10 a.m, the thermometer is taken back indoors where the temperature is fixed at 70°F, find the reading at 9:20 a.m.

• 58°F
• 50°F
• 55°F
• 64°F

A thermometer reading 18°F is brought into a room where the temperature is 70°F; a minute later, the thermometer reading is 31°F. Determine the temperature reading 5 minutes after the thermometer is first brought into the room.

• 57.68°F
• 45.68°F
• 64.10°F
• 60.61°F

A body having a temperature of 100 deg. C was placed in a room whose temperature is 0 deg. C. At the end of 1 minute, the temperature was reduce to 50 deg. C. What is the temperature of the body after 3 minutes?

• 12.5 deg. C
• 10.5 deg. C
• 10.35 deg. C
• 11.45 deg. C

According to Newton's law of cooling, the temperature of an object changes at a rate proportional to the difference in temperature between the object and the outside medium. If an object whose Temperature is 70°F is placed in a medium whose temperature is 20°F and is found to be 40°F after 3 minutes, what will its temperature be after 6 minutes?

• 25°F
• 26°F
• 27°F
• 28°F

An object having a temperature of 90°F is placed in an environment kept at 60°F. Ten minutes later the object has cooled to 88°F. What will be the temperature of the object after it has been in this environment for 20 minutes?

• 88.04°F
• 66.13°F
• 76.04°F
• 86.13°F

An object having a temperature of 90°F is placed in an environment kept at 60°F. Ten minutes later the object has cooled to 88°F. How long will it take for the object to cool to 65°F?

• 244.8 min
• 144.8 min
• 159.7 min
• 259.7 min

On a day when the temperature is 30°C, a cool drink is taken from a refrigerator whose temperature is 5°C. If the temperature of the drink is 20°C after 10 minutes, what will its temperature be after 20 minutes?

• 24°C
• 25°C
• 26°C
• 27°C

A body at an unknown temperature is placed in a room which is held at a constant temperature of 30°F. If after 10 minutes the temperature of the body is 0°F and after 20 minutes the temperature of the body is 15°F, find the unknown initial temperature.

• 5°F
• -10°F
• -30°F
• -25°F

A corpse is discovered at midnight and its body temperature is 84°F. If the body temperature at death is 98°F, the room temperature is constant at 66°F, and the proportionality constant is 0.10 per hour, determine the time of death.

• 6:00 PM
• 6:15 PM
• 6:30 PM
• 6:47 PM