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Dennis_Churaev [7]

2 years ago

10

The distance between two cities is 144km; it takes me 3 hours to travel between these cities. What average speed did I travel at

?

1 answer:

alexandr402 [8]2 years ago

3 0

Answer:

48km/hr

Explanation:

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What three variable factors determine the force of gravity between any two objects?

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F = G*m1*m2/r^2

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3 years ago

Para cargar un camión, se suele utilizar una tabla entre el contenedor y el suelo, con el fin de subir la carga, ya sea desplaza

stiks02 [169]

Answer:

A. No

B. si

Explanation:

A. El trabajo realizado en la carga es la energía potencial ganada por la carga al elevar la carga al nivel del camión y colocar la carga dentro del camión.

El trabajo realizado para elevar la carga W = m × g × h

Dónde;

m = masa de la carga

g = aceleración debido a la gravedad

h = Nivel de altura donde se coloca la carga en el camión

Por lo tanto, el trabajo realizado depende de la masa, m, de la carga y el nivel de altura, h, donde la carga se coloca en el camión y el trabajo realizado es el mismo para todos los métodos utilizados para colocar la carga en el camión

B. La ecuación para el trabajo realizado, W, también se puede escribir de la siguiente manera;

W = Fuerza, F × Distancia, D

De lo que tenemos;

F = W/D

Por lo tanto, cuando la mesa aumenta la distancia, como una rampa o un plano inclinado, la fuerza requerida disminuirá.

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3 years ago

What's phase changes mean? I can't find it

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3 years ago

Block with mass m =7.6 kg is hung from a vertical spring. when the mass hangs in equilibrium, the spring stretches x = 0.29 m. w

PSYCHO15rus [73]

1) 256.9 N/m

The force applied to the spring is equal to the weight of the block hanging on the spring:

$F=mg=(7.6 kg)(9.8 m/s^2)=74.5 N$

And the spring constant can be found by using Hook's law, because we know that the displacement caused by this force is x = 0.29 m:

$F=kx\\k=\frac{F}{x}=\frac{74.5 N}{0.29 m}=256.9 N/m$

2) 1.08 Hz

The angular frequency of oscillation of the spring is given by the formula:

$\omega=\sqrt{\frac{k}{m}}=\sqrt{\frac{256.9 N/m}{7.6 kg}}=5.81 rad/s$

And the frequency of oscillation is given by:

$\omega=2\pi f\\f=\frac{2 \pi}{\omega}=\frac{2\pi}{5.81 rad/s}=1.08 Hz$

3) 2.19 m/s

The velocity at time t of the block is given by:

$v=v_0 cos (\omega t)$

where

$v_0 = 4.4 m/s$ is the initial velocity of the block

$\omega=5.81 rad/s$ is the angular frequency

t is the time

Substituting t=0.36 s, we find the speed of the block at that time:

$v(0.36 s)=(4.4 m/s) ( cos ((5.81 rad/s)(0.36 s)) = -2.18 m/s$

And the negative sign means that the direction of the velocity is upward (because the initial velocity was downward)

4) 25.6 m/s^2

The maximum acceleration is given by:

$a_0 = \omega^2 A$

where A is the amplitude of the oscillation.

We can find the amplitude by using the law of conservation of energy: in fact, the kinetic energy at the equilibrium point must be equal to the elastic potential energy at the point of maximum displacement:

$K=U\\\frac{1}{2}mv_0^2 = \frac{1}{2}kA^2\\A=\sqrt{\frac{mv_0^2}{k}}=\sqrt{\frac{(7.6 kg)(4.4 m/s)^2}{256.9 N/m}}=0.76 m$

So, the maximum acceleration is

$a_0 = \omega^2 A=(5.81 rad/s)^2 (0.76 m)=25.6 m/s^2$

5) 95.1 N

The magnitude of the net force acting on the block is given by the difference between the weight and the restoring force of the spring:

$F=mg-kx$

First, we need to find the position x at t=0.36 s, which is given by

$x(t)=A sin(\omega t)=(0.76 m)(sin ((5.81 rad/s)(0.36 s))=0.66 m$

And so, the net force is

$F=(7.6 kg)(9.8 m/s^2)-(256.9 N/m)(0.66 m)=-95.1 N$

And the negative sign means the direction of the force is upward.

8 0

3 years ago

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