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3 years ago

Two objects made of the same material are heated to 60 oC and 90 oC. According to

Physics

2 answers:

earnstyle [38]3 years ago

6 0

Answer:

The newton law of cooling is:

dQ/dt = -h*a(To - Ta)

Where h and a are constants, To is the temperature of the object and Ta is the temperature of the ambient.

this means that initially if in both cases Ta is the same, the object with higher temperature cools faster.

Now, obviously, if we want to know which object cools faster to a given temperature, for example, 30°C, the object with 60°C will reach that temperature in less time than the other one. (this is because the hot object cools faster at the beginning, but as it starts to lose temperature, the rate at which it colls starts to decrease)

nlexa [21]3 years ago

4 0

Assuming that there is in a vacuum, the two object will cool at the same rate, because the objects are made of the same material they will have the same cooling rate, assuming the surrounding temperature is the same.

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3 years ago

Read 2 more answers

Transverse waves are being generated on a rope under constant tension. By what factor is the required power increased or decreas

ICE Princess25 [194]

Answer:

a) when the length of the rope is doubled and the angular frequency remains constant: The power increases by factor of two

b) when the amplitude is doubled and the angular frequency is halved: The power is the same

c) when both the wavelength and the amplitude are doubled: The power increases by a factor of 8

d) when both the length of the rope and the wavelength are halved: The power increases by factor of two

Explanation:

For a sinusoidal mechanical wave (Transverse wave), the time-averaged power is the energy associated with a wavelength divided by the period of the wave.

$P_{avg} =\frac{E \lambda}{T}=\frac{1}{2} \mu A^2 \omega^2 \frac{\lambda}{T}$

where;

A is the Amplitude

ω is the angular frequency

λ is the wavelength

a) when the length of the rope is doubled and the angular frequency remains constant

L = λ/2, λ = 2L

The power increases by factor of two

b) when the amplitude is doubled and the angular frequency is halved

$P_{avg} ={\frac{1}{2} \mu (2A)^2 (\frac{\omega}{2}) ^2 \frac{\lambda}{T} = \frac{1}{2} \mu A^2 \omega^2 \frac{\lambda}{T}$

The power is the same

c) when both the wavelength and the amplitude are doubled

$P_{avg} =\frac{1}{2} \mu (2A)^2 \omega^2 \frac{(2\lambda)}{T} = \frac{1}{2} \mu (4A^2) \omega^2 \frac{(2\lambda)}{T} = 8 (\frac{1}{2} \mu A^2 \omega^2 \frac{\lambda}{T})$

The power increases by a factor of 8

d) when both the length of the rope and the wavelength are halved

L = λ/2

when both are halved

L/2 = λ/4, λ = 2L

The power increases by factor of two

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Answer:

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Explanation:

there is too much potential energy that transforms into kinetic energy for him to stay on the track.

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