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vodomira
10 days ago
7

What is the minimum amount of energy required to completely melt a 7.25-kg lead brick which has a starting temperature of 18.0 °

C? The melting point of lead is 328 °C. The specific heat capacity of lead is 128 J/(kg∙C°); and its latent heat of fusion is 23,200 J/kg.a. 1.68 × 105 J b. 2.88 × 105 J c. 4.56 × 105 J d. 5.96 × 105 J e. 7.44 × 105 J
Physics
1 answer:
Ostrovityanka [2.8K]10 days ago
5 0

Answer: c. 4.56 × 105 J

Explanation:

Given the mass of the lead brick, m = 7.25 kg

Starting temperature T1 = 18.0 °C

Ending temperature T2 = 328 °C

The specific heat capacity for lead, c = 128 J/(kg∙°C)

And the latent heat of fusion Lfusion = 23,200 J/kg

The required energy Q =?

Using the following equations

Energy required, Q = mc (T2 - T1) + mLfusion

Substituting in the values we have: 7.25 kg * 128 J/(kg∙°C) * (328 - 18°C) + 7.25 kg * 23200 J/kg

= 455880 J

= 4.56 x 10^5 J

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Sebuah benda dijatuhkan bebas dari ketinggian 200 m jika grafitasi setempat 10 m/s maka hitunglah kecepatan dan ketinggian benda
inna [2740]
Kindly use English in your post so that I or someone else can assist you.
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15 days ago
A small crack occurs at the base of a 15.0-m-high dam. The effective area through which water leaves is 2.30 × 10-3 m2. (a) Igno
Ostrovityanka [2820]

Answer

Given data:

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effective area for water flow = 2.3 x 10⁻³ m²

Applying the principle of energy conservation:

m g h = \dfrac{1}{2}mv^2

v= \sqrt{2gh}

v= \sqrt{2\times 9.8 \times 15}

v= \sqrt{294}

v = 17.15 m/s

water discharge

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3 0
27 days ago
James Cameron piloted a submersible craft to the bottom of the Challenger Deep, the deepest point on the ocean's floor, 11,000 m
serg [3228]

Answer:

4.1\cdot 10^8 N

Explanation:

To begin with, we must determine the pressure acting on the sphere, which is calculated using:

p=p_0 + \rho g h

where

p_0 =1.01\cdot 10^5 Pa denotes the atmospheric pressure

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g=9.8 m/s^2 signifies the acceleration due to gravity

h=11,000 m indicates the depth

By substituting these values,

p=1.01\cdot 10^5 Pa + (1000 kg/m^3)(9.8 m/s^2)(11,000 m)=1.08\cdot 10^8 Pa

The sphere's radius is calculated as r = d/2 = 1.1 m/2 = 0.55 m

Thus, the sphere's total surface area can be expressed as

A=4 \pi r^2 = 4 \pi (0.55 m)^2=3.8 m^2

Consequently, the inward force acting on the sphere equals

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8 0
12 days ago
Read 2 more answers
a pebble is dropped down a well and hits the water 1.5 seconds later. using the equations for motion with constant acceleration,
inna [2740]
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Consideremos la gravedad g como 9.8 m/s² y despreciemos la resistencia del aire.

La velocidad inicial vertical del guijarro es nula.
Ya que el guijarro impacta el agua tras 1.5 segundos, entonces:
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Resultado: 11.025 m
7 0
1 month ago
Read 2 more answers
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