Which law states that absolute zero cannot be reached?

How long would it take a 4,560 watt motor to raise a 166 kg piano to an apartment window

IrinaK [193]

Answer:

Explanation:

We need the power equation here:

P = W/t where W is work and is defined as

W = F*displacement.

Force is a measure in Newtons, which is also weight. We have the mass of the piano, but we need to find the weight:

w = mg so

w = 166(9.8) so

w = 1600N, rounded to the correct number of sig dig. We use that now in the power equation:

$4560=\frac{(1600)(15)}{t}$ and isolating the unknown:

$t=\frac{(1600)(15)}{4560}$ so

t = 5.3 seconds

8 0

3 years ago

Asteroids do not travel in a straight line as they orbit the Sun. Per Newton's second law of motion, this implies

Morgarella [4.7K]

A force is acting on the planet

7 0

2 years ago

How does a substance's temperatura chanté when the average kinetic energy of its particles increases? When it decreases?

Aleks [24]

Kinetic energy means movement. This means that the more something moves, the more kinetic energy it will have! And the faster something moves, the more heat it produces! Altogether, this means that the more Kinetic energy something has, the hotter it will be!

The opposite is also true. The less something moves, it will have less Kinetic energy and the colder it will get.

If you're having trouble understanding this, think of it like how the particles in water move compared to how the particles in ice move. The particles in water are free flowing and can move wherever they want. If they get colder, they won't move as much, and eventually they'll stop flowing around, forming a solid and staying colder than the water will get.

7 0

3 years ago

Una placa de cobre a 20°C tiene unas dimensiones de 65cm x 78 cm. Encuentra el área de la placa a 400°C; Coeficiente de dilataci

ValentinkaMS [17]

Answer:

El área de la placa es aproximadamente 5102.752 centímetros cuadrados.

Explanation:

Asumamos que el cambio dimensional como consecuencia de la temperatura es pequeña, entonces podemos estimar el área de la placa de cobre en función de la temperatura mediante la siguiente aproximación:

$A_{f} = w\cdot l \cdot [1 + 2\cdot \alpha\cdot (T_{f}-T_{o})]$ (1)

Donde:

$w$ - Ancho de la placa, en centímetros.

$l$ - Longitud de la placa, en centímetros.

$\alpha$ - Coeficiente de dilatación, en $\frac{1}{^{\circ}C}$ .

$T_{o}$ - Temperatura inicial, en grados Celsius.

$T_{f}$ - Temperatura final, en grados Celsius.

Si sabemos que $w = 65\,cm$ , $l = 78\,cm$ , $\alpha = 17\times 10^{-6}\,\frac{1}{^{\circ}C}$ , $T_{o} = 20\,^{\circ}C$ and $T_{f} = 400\,^{\circ}C$ , entonces el área de la placa a la temperatura final: