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3 years ago

A stone is dropped from the top of a tower. What is its velocity after 3.0 seconds?

1 answer:

5 0

For purposes of completing our calculations, we're going to assume that
the experiment takes place on or near the surface of the Earth.

The acceleration of gravity on Earth is about 9.8 m/s², directed toward the
center of the planet. That means that the downward speed of a falling object
increases by 9.8 m/s for every second that it falls.

3 seconds after being dropped, a stone is falling at (3 x 9.8) = 29.4 m/s.

That's the vertical component of its velocity. The horizontal component is
the same as it was at the instant of the drop, provided there is no horizontal
force on the stone during its fall.

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A 3 om light bulb and a 6 om light bulb are connected in series, and then hooked up to a battery. Which of the two will shine th

RUDIKE [14]

Answer:

the 6 om is brighter because 6-3=3

Explanation:

3 0

3 years ago

Un engrane que gira con una velocidad de 20 rad/s, es acelerado durante 5 segundos hasta alcanzar una velocidad de 35 rad/s

larisa [96]

Answer:

a) La aceleración angular es: $\alpha=2\: rad/s^{2}$

b) El engranaje gira 125 radianes.

c) El engranaje hara aproximadamente 20 revoluciones.

Explanation:

La aceleración angular se define como:

$\alpha=\frac{\Delta \omega}{\Delta t}$

Donde:

Δω es la diferencia de velocidad angular (en otras palabras ω(final)-ω(inicial))
Δt es el tiempo en el que occure el cambio de velocidad angular

$\alpha=\frac{35-25}{5}$

$\alpha=2\: rad/s^{2}$

El desplazamiento angular puede ser calculado usando la siguiente ecuación:

$\theta=\theta_{i}+\omega_{i}t+\frac{1}{2}\alpha t^{2}$

Aqui el angulo inicial es 0, por lo tanto.

$\theta=20(5)+\frac{1}{2}(2)(5)^{2}$

$\theta=125\: rad$

El engranaje gira 125 radianes.

Lo que debemos hacer aquí es convertir radianes a revoluciones.

Recordemos que 2π rad = 1 rev

Entonces:

$\theta=125\: rad \times \frac{1\: rev}{2\pi\: rad}=19.89\: rev$

Por lo tanto el engranaje hara aproximadamente 20 revoluciones.

Espero te haya sido de ayuda!

6 0

3 years ago

A+10 u charge and a -10 4C (1 HC - 106 C), at a distance of 0.3 m,

Marina CMI [18]

Answer:

B. Attract each other with a force of 10 newtons.

Explanation:

Statement is incorrectly written. <em>The correct form is: A </em> $+10\,\mu C$ <em> charge and a </em> $-10\,\mu C$ <em> at a distance of 0.3 meters. </em>

The two particles have charges opposite to each other, so they attract each other due to electrostatic force, described by Coulomb's Law, whose formula is described below:

$F = \frac{\kappa \cdot |q_{A}|\cdot |q_{B}|}{r^{2}}$ (1)

Where:

$F$ - Electrostatic force, in newtons.

$\kappa$ - Electrostatic constant, in newton-square meters per square coulomb.

$|q_{A}|,|q_{B}|$ - Magnitudes of electric charges, in coulombs.

$r$ - Distance between charges, in meters.

If we know that $\kappa = 8.988\times 10^{9}\,\frac{N\cdot m^{2}}{C^{2}}$ , $|q_{A}| = |q_{B}| = 10\times 10^{-6}\,C$ and $r = 0.3\,m$ , then the magnitude of the electrostatic force is: