Penn Physical Science Lesson 2 700170RR/Penn Physical Science Lesson 2 700170RR

Penn Physical Science Lesson 2 700170RR




Question

Question 1

1. How much heat energy (in megajoules) is needed to convert 7 kilograms of ice at –9°C to

water at 0°C?

A. 2.48 MJ

B. 3.26 MJ

C. 2.13 MJ

D. 3.09 MJ

Q = mLf+mci T; Q = (7 kg*3.34×10 J/kg) + ((7kg*2100J/kgK*{0°C-(9°C)}); = 2.48 MJ

Question 2

2. A mass of gas under constant pressure occupies a volume of 0.5 m3 at a temperature of

20°C. Using the formula for cubic expansion, what will be the volume at a temperature of

45°C without a change in pressure?

A. 0.0228938 m3

B. 0.0457875 m3

C. 0.5228938 m3

D. 0.5457875 m3

V1/T1 =V2/T2 , 20C= 293.15K , 45 C= 318.15 ,

0.5/ 293.15 =V2/318.15 , V2 =0.5 * 318..15 = 0.545.

Question 3

3. Convert the temperature 288 K to degrees Celsius.

A. 748°C