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3 years ago

9

Calculate the specific heat capacity of a piece of wood if 150.0g of the wood absorbs 67,000 joules of heat, and it’s temperatur

e changes from 30c to 55c

1 answer:

svet-max [94.6K]3 years ago

5 0

Answer:

$17.8 J/g^{\circ}C$

Explanation:

When a certain amount of substance is supplied with a certain amount of energy Q, the temperature of the substance increases according to the equation

$Q=mC\Delta T$

where

m is the mass of the substance

C is the specific heat capacity

$\Delta T$ is the change in temperature

In this problem:

m = 150.0 g is the mass of wood

Q=67,000 J is the amount of energy supplied to the wood

$\Delta T=55-30=25^{\circ}C$ is the increase in temperature of the substance

Therefore, the specific heat capacity is:

$C=\frac{Q}{m\Delta T}=\frac{67,000}{(150.0)(25)}=17.8 J/g^{\circ}C$

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A. Any Direction
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4 years ago

A) The motor speed is less than wheel speed.

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For the following statements

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<h3>What are speed, power, and Torque?</h3>

Speed: defined as the ratio of operation with respect to distance and time

Power: defined as the ability to work

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Generally, the equation for Speed, Power, Torque is mathematically given as

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3 years ago

Black holes are highly condensed remnants of stars. Some black holes, together with a normal star, form binary systems. In such

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$\lambda_\text{max} = 2.63\times 10^{-9}\;\text{m}$ .

<h3>Explanation</h3>

The peak emission wavelength of an object depends on its absolute temperature.

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$\lambda_\text{max}$ is the wavelength in meters where the emission is the strongest.
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For the gas falling into the black hole,

$T = 1.10\times 10^{6}\;\text{K}$ .

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$\lambda_\text{max} = \dfrac{2.90\times 10^{-3}}{T} = \dfrac{2.90\times 10^{-3}}{1.10\times 10^{6}} = 2.64\times 10^{-9}\;\text{m} = 2.64 \;\text{nm}$ .

The question mentioned that $\lambda_\text{max}$ is in the X-ray region of the electromagnetic spectrum. According to Encyclopedia Britannica, the wavelength of X-rays range from $10^{-8}\;\text{m}=10\;\text{nm}$ to $10^{-10}\;\text{m} = 0.1\;\text{nm}$ , which indeed includes $2.64\times 10^{-9}\;\text{m} = 2.64 \;\text{nm}$ .

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3 years ago

A boat crossing a 153.0 m wide river is directed so that it will cross the river as quickly as possible. The boat has a speed of

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We have the relation

$\vec v_{B \mid E} = \vec v_{B \mid R} + \vec v_{R \mid E}$

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$v_{B \mid R} = 5.10 \dfrac{\rm m}{\rm s}$

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Let's assume the river flows South-to-North, so that

$\vec v_{R \mid E} = v_{R \mid E} \, \vec\jmath$

and let $-90^\circ < \theta < 90^\circ$ be the angle made by the boat relative to East (i.e. -90° corresponds to due South, 0° to due East, and +90° to due North), so that

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Then the velocity of the boat relative to the Earth is

$\vec v_{B\mid E} = v_{B \mid R} \cos(\theta) \, \vec\imath + \left(v_{B \mid R} \sin(\theta) + v_{R \mid E}\right) \,\vec\jmath$

The crossing is 153.0 m wide, so that for some time $t$ we have

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and the boat would have traveled a total distance of

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