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2 years ago

Please help me . i need to answer it asap thankyou

Physics

1 answer:

alex41 [277]2 years ago

8 0

The amount of heat needed to melt the block of lead is $5.4\cdot 10^4 J$

Explanation:

The amount of heat needed to melt a solid substance already at its melting point is given by the equation

$Q=m \lambda_f$

where

m is the mass of the substance

$\lambda_f$ is the specific latent heat of fusion

In this problem, we have a block of lead already at its melting point, $327^{\circ}C$ . Its mass is

m = 200 g = 0.2 kg

and its specific latent heat of fusion is

$\lambda_f = 2.7\cdot 10^5 J/kg$

Therefore, the amount of heat needed for the block to completely melt is

$Q=(0.2)(2.7\cdot 10^5)=5.4\cdot 10^4 J$

Learn more about specific heat:

brainly.com/question/3032746

brainly.com/question/4759369

#LearnwithBrainly

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A helicopter flies over the arctic ice pack at a constant altitude, towing an airborne 130-kg laser sensor that measures the thi

umka21 [38]

Answer:T=1316.21 N

Explanation:

The tension has two components: Vertical and Horizontal. The

horizontal component is ma, the vertical component is mg. Using

Pythagoras theorem, we can find the tension as:

T=((ma)^2 (mg)^2)^(1/2)

T=((129*2.84)^2 (129*9.8)^2)^(1/2)

T=1316.21 N

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2 years ago

Define Plateau period.

Amiraneli [1.4K]

A plateau period refers to a period in life where you are kind of stuck in the middle. There is little growth or decline so you are kind of at a standstill.

please vote my answer brainliest. thanks!

5 0

2 years ago

Invader Zim’s spaceship is sitting at rest in outer space. The ship then accelerates at a uniform rate of 12 m/s2 for 10 seconds

melisa1 [442]

Answer:

120 m/s

Explanation:

Given:

v₀ = 0 m/s

a = 12 m/s²

t = 10 s

Find: v

v = at + v₀

v = (12 m/s²) (10 s) + 0 m/s

v = 120 m/s

6 0

3 years ago

While traveling home at dusk, a motorcyclist gets on the highway and increases the combined mass (400 kg

alexdok [17]

The acceleration of one of those bugs is equal to 305mi/s.

<h3>Acceleration calculation</h3>

To calculate the insect's acceleration, the action and reaction force of the impact must be considered.

As the insect will hit the helmet, the force it hits is the same force it receives, so we can make the following expression:

$m_m \times a_m = m_b \times a_b$

$550 \times 0.0027 = 5 \times 10^{-3} \times a_b$

<em>Speed has been converted to miles per second</em>

$a_b = 305 mi/s$

So, the acceleration of one of those bugs is equal to 305mi/s.

Learn more about acceleration calculation: brainly.com/question/390784

8 0

1 year ago

Three moles of a monatomic ideal gas are heated at a constant volume of 1.20 m3. The amount of heat added is 5.22x10^3 J.(a) Wha

k0ka [10]

Answer:

A) 140 k

b ) 5.22 *10^3 J

c) 2910 Pa

Explanation:

Volume of Monatomic ideal gas = 1.20 m^3

heat added ( Q ) = 5.22*10^3 J

number of moles (n) = 3

A ) calculate the change in temp of the gas

since the volume of gas is constant no work is said to be done

heat capacity of an Ideal monoatomic gas ( Q ) = n.(3/2).RΔT

make ΔT subject of the equation

ΔT = Q / n.(3/2).R

= (5.22*10^3 ) / 3( 3/2 ) * (8.3144 J/mol.k )

= 140 K

B) Calculate the change in its internal energy

ΔU = Q this is because no work is done

therefore the change in internal energy = 5.22 * 10^3 J

C ) calculate the change in pressure

applying ideal gas equation

P = nRT/V

therefore ; Δ P = ( n*R*ΔT/V )

= ( 3 * 8.3144 * 140 ) / 1.20

= 2910 Pa

3 0

3 years ago

Please help me . i need to answer it asap thankyou​

Please help me . i need to answer it asap thankyou