Answer:
7.6 g
Explanation:
"Well lagged" means insulated, so there's no heat transfer between the calorimeter and the surroundings.
The heat gained by the copper, water, and ice = the heat lost by the steam
Heat gained by the copper:
q = mCΔT
q = (120 g) (0.40 J/g/K) (40°C − 0°C)
q = 1920 J
Heat gained by the water:
q = mCΔT
q = (70 g) (4.2 J/g/K) (40°C − 0°C)
q = 11760 J
Heat gained by the ice:
q = mL + mCΔT
q = (10 g) (320 J/g) + (10 g) (4.2 J/g/K) (40°C − 0°C)
q = 4880 J
Heat lost by the steam:
q = mL + mCΔT
q = m (2200 J/g) + m (4.2 J/g/K) (100°C − 40°C)
q = 2452 J/g m
Plugging the values into the equation:
1920 J + 11760 J + 4880 J = 2452 J/g m
18560 J = 2452 J/g m
m = 7.6 g
Answer:
R2 = 10.31Ω
Explanation:
For two resistors in parallel you have that the equivalent resistance is:
(1)
R1 = 13 Ω
R2 = ?
The equivalent resistance of the circuit can also be calculated by using the Ohm's law:
(2)
V: emf source voltage = 23 V
I: current = 4 A
You calculate the Req by using the equation (2):

Now, you can calculate the unknown resistor R2 by using the equation (1):

hence, the resistance of the unknown resistor is 10.31Ω
Answer by mimiwhatsup: B) Velocity is a vector and requires a direction to completely describe it.
Velocity is the speed and direction of an object in motion.
Answer:
this measurement if feet is: 2.624672 ft
Explanation:
Notice that 80 cm can be expressed as 0.8 meters, and In order to convert from meters to feet, one needs to multiply the meter measurement times 3.28084. Therefore:
0.80 m can be written in feet as: 0.80 * 3.28084 feet = 2.624672 feet
Answer:
it floats because the lake is cold at that moment so when part of the lake freezes it still remains solid and floats because of the lake and the surrounding of the lake is still cold