Which of the following statements about energy is false?

The rectangular boat shown below has base dimensions 10.0 cm × 8.0 cm. Each cube has a mass of 40 g, and the liquid in the tank

Paladinen [302]

When boat is sunk into the liquid the net buoyancy on the boat is counterbalanced by weight of the boat

So here weight of the boat = Buoyancy force

let say boat is sunk by distance "h"

now we can say

$F_b = \rho * V * g$

$F_b = 1000*0.10 * 0.08 * h * 9.8$

now by above force balance equation we can write

$m*g = F_b$

$0.040 * 9.8 = 1000 * 0.10 * 0.08 * h * 9.8$

$0.040 = 8h$

$h = 5 * 10^{-3} m$

so boat will sunk by total 5 mm distance

8 0

3 years ago

In a nuclear fusion reaction, atoms: split apart. combine. explode. cool down.

Sergeeva-Olga [200]

The answer is combine

5 0

3 years ago

Read 2 more answers

When being unloaded from a moving truck, a 16.0- kilogram suitcase is placed on a flat ramp inclined at 40.0 o. When released fr

9966 [12]

Answer:

0.65812

Explanation:

m = Mass of suitcase = 16 kg

$\theta$ = Incline angle = 40°

g = Acceleration due to gravity = 9.81 m/s²

a = Acceleration of the block = 1.36 m/s²

f = Frictional force

The normal force is given by

$N=mgcos\theta$

In x direction

$mgsin\theta-f=ma\\\Rightarrow f=mgsin\theta-ma\\\Rightarrow f=16\times 9.81\times sin40-16\times 1.36\\\Rightarrow f=79.13194\ N$

Frictional force is given by

$f=\mu N=\mu mgcos\theta\\\Rightarrow \mu=\dfrac{f}{mgcos\theta}\\\Rightarrow \mu=\dfrac{79.13194}{16\times 9.81\times cos40}\\\Rightarrow \mu=0.65812$

The coefficient of kinetic friction between the suitcase and the ramp is 0.65812

8 0

3 years ago

A rigid tank initially contains 3kg of carbon dioxide (CO2) at a pressure of 3bar.The tank is connected by a valve to a friction

marissa [1.9K]

Answer:

Part a: The total amount of energy transfer by the work done is 54.81 kJ.

Part b: The total amount of energy transfer by the heat is 54.81 kJ

Explanation:

Mass of Carbon Dioxide is given as m1=3 kg

Pressure is given as P1=3 bar =300 kPA

Volume is given as V1=0.5 m^3

Pressure in tank 2 is given as P2=2 bar=200 kPa

T=290 K

Now the Molecular weight of $CO_2$ is given as

M=44 kg/kmol

the gas constant is given as

$R=\frac{\bar{R}}{M}\\R=\frac{8.314}{44}\\R=0.189 kJ/kg.K$

Volume of the tank is given as

$V=\frac{mRT}{P_1}\\V=\frac{3 \times 0.189 \times 290}{300 }\\V=0.5481 m^3$

Final mass is given as

$m_2=\frac{P_2V}{RT}\\m_2=\frac{200\times 0.5481}{0.189\times 290}\\m_2=2 kg$

Mass of the CO2 moved to the cylinder

$m=m_1-m_3\\m=3-2=1 kg$

The initial mass in the cylinder is given as

$m_{(cyl)_1}=\frac{P_{(cyl)_1}V_1}{RT}\\m_{(cyl)_1}=\frac{200\times 0.5}{0.189 \times 290}\\m_{(cyl)_1}=1.82 kg$

The mass after the process is

$m_{(cyl)_2}=m_{(cyl)_1}+m\\m_{(cyl)_2}=1.82+1\\m_{(cyl)_2}=2.82\\$

Now the volume 2 of the cylinder is given as

$V_{(cyl)_2}=\frac{m_{(cyl)_2}RT}{P_2}\\m_{(cyl)_2}=\frac{2.82\times 0.189\times 290}{200}\\m_{(cyl)_1}=0.774 m^3$

Part a:

So the Work done is given as

$W=P(V_2-V_1)\\W=200(0.774-0.5)\\W=54.81 kJ$

The total amount of energy transfer by the work done is 54.81 kJ.

Part b:

The total energy transfer by heat is given as

$Q=\Delta U+W\\Q=0+W\\Q=54.81 kJ$

As the temperature is constant thus change in internal energy is 0.

The total amount of energy transfer by the heat is 54.81 kJ

7 0

3 years ago

What would most likely cause the future acceleration of the expansion of the universe

CaHeK987 [17]

The answer is dark energy. This is the energy in the universe that opposes the gravitational attraction of matter in the universe. Initially, cosmologists had thought that the universe was decelerating due to the gravitational attraction between matter in the universe after the big bang. However, using the Doppler shift effect, evidence was gathered on the nature of the expansion of the universe.

5 0

3 years ago