Question

conservation of mass
berny has a 0.15 - kilogram candle, a 1.00 - kilogram jar, and a 0.25 kilogram ca in the jar, lights the candle, and then immediately closes the jar.
what should the total mass of the jar and its contents be after the candle goes
a. 1.25 kilograms
b. 1.40 kilograms
c. 1.00 kilograms
d. 1.15 kilograms
4 of 10 answered
session timer: 3:22

Explanation:

Step1: Recall conservation of mass.

In a closed - system, mass is conserved. The initial mass of the system is the sum of the mass of the candle, the jar, and the cap.

Step2: Calculate the initial mass.

The mass of the candle $m_{c}=0.15$ kg, the mass of the jar $m_{j}=1.00$ kg, and the mass of the cap $m_{cap}=0.25$ kg. The total initial mass $m = m_{c}+m_{j}+m_{cap}=0.15 + 1.00+0.25$.
$m=1.40$ kg. Since mass is conserved in the closed - system (the jar is closed), the final mass of the jar and its contents is also 1.40 kg.

Answer:

B. 1.40 kilograms