Does anyone know any sites that you can use for physics for like homework

Elodia [21]

Answer:

$K_{i}+U_{g,i} = K_{f}+U_{g,f}$

Explanation:

A closed system is a system where exists energy interactions with surroundings, but not mass interactions. If we neglect any energy interactions from boundary work, heat, electricity, magnetism and nuclear phenomena and assume that process occurs at steady state and all effects from non-conservative forces can be neglected, then the equation of energy conservation is reduce to this form:

$\Delta K +\Delta U_{g} = 0$ (1)

Where:

$\Delta K$ - Change in kinetic energy of the system, measured in joules.

$\Delta U_{g}$ - Change in gravitational potential energy of the system, measured in joules.

If we know that $\Delta K=K_{i}-K_{f}$ and $\Delta U_{g} = U_{g,i}-U_{g,f}$ , then we get the following equation:

$K_{i}+U_{g,i} = K_{f}+U_{g,f}$ (2)

Where $i$ and $f$ stands for initial and final states of each energy component.

Hence, the right answer is $K_{i}+U_{g,i} = K_{f}+U_{g,f}$

7 0

3 years ago

Read 2 more answers

A penguin slides at a constant velocity of 3.57 m/s down an icy incline. The incline slopes above the horizontal at an angle of

igomit [66]

Answer:t=0.81 s

Explanation:

Given

Penguin slides down with constant velocity of 3.57 m/s

as the Penguin Slides with constant velocity therefore $F_{net}$ is zero on Penguin

$F_{net}=mg\sin \theta -f_r$

$f_r=$ friction Force

$f_r=\mu mg$

$\mu =$ coefficient of Kinetic friction

$mg\sin \theta =\mu mg$

$\tan \theta =\mu$

$\mu =\tan 9.85=0.45$

after reaching on floor final velocity of penguin will be zero after time t

thus

$v=u+at$

here $a=\mu g$

$a=0.45\times 9.8=4.41$ (deceleration)

$0=3.57-4.41\times t$

$t=\frac{3.57}{4.41}=0.809$

$t=0.81 s$

8 0

3 years ago

A toaster draws 8 A of current with a voltage of 120 V. Which is the power used by the toaster

Tatiana [17]

Power = (voltage) x (current) =

(120 V) x (8 A) = <em>960 watts</em>

7 0

3 years ago

What is the driving force for (a) heat transfer, (b) electric current, and (c) fluid flow?

lara31 [8.8K]

Answer:

The driving force for (a) heat transfer is temperature difference. (b) electric current is voltage difference. (c) fluid flow is pressure or hydraulic head difference.

Explanation: (a) The driving force for heat transfer is temperature difference. Heat transfer between two mediums is possible only if the two mediums are at different temperature, the higher the temperature, the higher the heat transfer.

(b) The driving force for electric current is voltage difference. Voltage difference is defined as the potential difference in charge between two points in electrical field. For electric current to occur,the voltage must be high.

(c) The driving force for fluid flow is pressure difference or hydraulic head difference. For fluid to move upward,it requires energy.

3 0

3 years ago

Typical Pressurized Water Reactors can produce 1100 to 1500

lozanna [386]

Answer: about 1,100,000,000 to 1,500,000,000 Joules/second

Explanation:

1 MW (megawatt) = 1,000,000.00 J/s (joules per second)

1100(1,000,000) = 1,100,000,000

1500(1,000,000) = 1,500,000,000

3 0

3 years ago