When an unstable radioactive atom degrades, what happens to it?

A thermos contains m1 = 0.89 kg of tea at T1 = 31° C. Ice (m2 = 0.075 kg, T2 = 0° C) is added to it. The heat capacity of both w

lorasvet [3.4K]

Answer:

a) T = (m1cT1 + m2cT2 - m2Lf)/(m1c + m2c)

b) T = 295.37 K

Explanation:

Given;

Initial temperature of tea T1 = 31 C

Initial temperature of ice T2 = 0 C

Mass of tea m1 = 0.89 kg

Mass of ice m2 = 0.075kg

The heat capacity of both water and tea c = 4186 J/(kg⋅K)

the latent heat of fusion for water is Lf = 33.5 × 10^4 J/kg

And T = the final temperature of the mixture

Heat loss by tea = heat gained by ice

m1c∆T1 = m2c∆T2 + m2Lf

m1c(T1-T) = m2c(T-T2) + m2Lf

m1cT1 - m1cT = m2cT - m2cT2 + m2Lf

m1cT + m2cT = m1cT1 + m2cT2 - m2Lf

T(m1c + m2c) = m1cT1 + m2cT2 - m2Lf

T = (m1cT1 + m2cT2 - m2Lf)/(m1c + m2c)

Substituting the values;

T = (m1cT1 + m2cT2 - m2Lf)/(m1c + m2c)

T = (0.89×4186×31 + 0.075×4186×0 - 0.075×33.5 × 10^4)/(0.89×4186 + 0.075×4186)

T = 22.37 °C

T = 273 + 22.37 K

T = 295.37 K

4 0

3 years ago

Read 2 more answers

A 11.0 kg test rocket is fired vertically from Cape Canaveral. Its fuel gives it a kinetic energy of 1985 J by the time the rock

nirvana33 [79]

Answer:

h = 18.41 m

Explanation:

Given that,

Mass of a test rocket, m = 11 kg

Its fuel gives it a kinetic energy of 1985 J by the time the rocket engine burns all of the fuel.

According to the law of conservation of energy,

PE = KE = mgh

h is height will the rocket rise

$h=\dfrac{E}{mg}\\\\h=\dfrac{1985 }{11\times 9.8}\\\\h=18.41\ m$

So, the rocket will rise to a height of 18.41 m.

5 0

3 years ago

A tetrahedron has an equilateral triangle base with 25.0-cm-long edges and three equilateral triangle sides. The base is paralle

Jet001 [13]

Answer:

-7.03645640575 Nm²/C

2.34548546858 Nm²/C

Explanation:

S = Surface area

Electric flux through the base is given by

$\phi_b=-\int Eds\\\Rightarrow \phi_b=-ES\\\Rightarrow \phi_b=-260\dfrac{\sqrt{3}}{4}0.25^2\\\Rightarrow \phi_b=-7.03645640575\ Nm^2/C$

The electric flux through the base is -7.03645640575 Nm²/C

Inside the tetrahedron there is no charge so total flux will be zero

$\phi_b+3\phi_s=0\\\Rightarrow \phi_s=-\dfrac{\phi_b}{3}\\\Rightarrow \phi_s=-\dfrac{-7.03645640575}{3}\\\Rightarrow \phi_s=2.34548546858\ Nm^2/C$

The electric flux through the sides is 2.34548546858 Nm²/C

6 0

3 years ago

A car travels 60 km in the first 2 hours and 68 km in the next 2 hours. What’s the cars average speed?

Klio2033 [76]

Answer:

The car's average speed is 32 kilometers per hour

Explanation:

1. Let's review the information given to us to answer the question correctly:

First two hours = 60 kilometers

Next two hours = 68 kilometers

2. What is the car's average speed?

Total distance traveled by the car = 60 + 68

Total distance traveled by the car = 128

Total time of travel = 2 + 2 hours

Total time of travel = 4 hours

Average speed = Total distance/Total time

Replacing with the real values, we have:

Average speed = 128/4

Average speed = 32 kilometers per hour

4 0

4 years ago

The Ptolemaic theory of the universe was disproved by

GuDViN [60]

The Ptolemaic theory of the universe was disproved by Nicolaus Copernicus (1473–1543), letter C and followed by Johannes Kepler (1571–1630). Geocentric theory suggested that the Sun and moon orbited Earth, and the rest of the planets orbited the Sun is Heliocentric theory. Heliocentric theory of Nicolaus Copernicus during the Scientific Revolution on 17th and 18th century while Geocentric theory was proposed by Ptolemy (AD 150) and Aristotle. Today, we believe more on the Heliocentric theory and it has been proven as well.

8 0

3 years ago