Ask question

Ask question

All categories

3 years ago

7

A high-diver of mass 59.8 kg jumps off a board 10.0 m above the water. If, 1.00 s after entering the water his downward motion i

s stopped, what average upward force did the water exert?
a. 108 N.
b. 4.27 N.
c. 840 N.
d. 598 N.
e. None of the other answers is correct.

1 answer:

irinina [24]3 years ago

6 0

la respuesta correcta es la "E"

You might be interested in

(quick help please??)A mechanic uses a mechanical lift to raise a car. The car weighs 10,200 N. The work required to do this was

GuDViN [60]

I believe It would be 2.2m

5 0

3 years ago

A wave has a wavelength of 4. 9 m and a velocity of 9. 8 m/s. The medium through which this wave is traveling is then heated so

tatiyna

The wavelength of a wave is obtained by taking the ratio of wave speed and frequency.

The wavelength of the heated wave is 9.8 m. Hence, option (b) is correct.

What is frequency of a wave?

The number of oscillations completed by a wave in one second is known as the frequency of a wave. It is expressed as the ratio of the velocity of the wave to its wavelength.

Given data-

The wavelength of the wave is, $\lambda = 4.9 \;\rm m$ .

The velocity of the wave is, v = 9.8 m/s.

The mathematical expression for the frequency of the wave is,

$f = \dfrac{v}{\lambda}$

Solving as,

$f = \dfrac{9.9}{4.9}\\\\f =2 \;\rm Hz$

Now, with constant frequency and the double magnitude of velocity (v' = 2 × 9.8 = 19.6 m/s). The wavelength of the heated wave is calculated as,

$f = \dfrac{v'}{\lambda'}$

here,

$\lambda'$ is the wavelength of the heated wave.

Solving as,

$2 = \dfrac{19.6}{\lambda'}\\\\\lambda' = \dfrac{19.6}{2}\\\\\lambda' = 9.8 \;\rm m$

Thus, we can conclude that the wavelength of the heated wave is 9.8 m. Hence, option (b) is correct.

Learn more about the frequency of wave here:

brainly.com/question/1324797

3 0

2 years ago

All fires require oxygen () There is no oxygen in that room (T) .

Marina CMI [18]

The sentences are invalid and unsound.

<h3><u>Explanation</u>:</h3>

The fire is defined as the vigorous oxidation of a substance. Now oxidation can occur in presence of any oxidising agent. Like magnesium in presence of nitrogen in high temperature with a dazzling brownish flame to produce magnesium nitride. So fire can be produced in absence of oxygen.

Oxygen is present everywhere in world. So production of a whole room without oxygen is very tough to produce and costly process. So its very unsound.

4 0

3 years ago

What mean by expansion effect of heat<br>

pishuonlain [190]

Answer:

Explanation:

-Cambio de temperatura

Al calentar un cuerpo la temperatura aumenta

Es el efecto más inmediato del calor, el aumento de la temperatura. Al calentar un cuerpo, es habitual, aunque no siempre, que el cuerpo aumente de temperatura. El aumento dependerá de la cantidad de calor que se suministra, del tipo de sustancia y de su cantidad.

-Dilatación

Cuando un objeto se calienta, su volumen aumenta. Este fenómeno se llama dilatación térmica. Por el contrario, cuando un objeto se enfría, su volumen disminuye, debido a la contracción térmica.

Cuando se calienta un cuerpo, además de cambiar de estado o variar su temperatura, también cambia su tamaño, se dilata.

Por ejemplo, los puentes no se construyen de una única pieza, sino que suelen presentar uno o varios cortes longitudinales, las llamadas juntas de dilatación. Si no existieran esas juntas, los cambios de longitud del puente entre el invierno y el verano o entre el día y la noche acabarían por romperlo.

La dilatación de un cuerpo dependerá del aumento de temperatura que experimente, de su tamaño y de la sustancia de que esté hecho. Cuanto más aumente la temperatura más aumentará su tamaño, lo mismo que cuanto mayor sea, mayor se hará.

Todos los cuerpos, ya sean sólidos, líquidos o gaseosos, varían su tamaño cuando intercambian calor con otro cuerpo.

-Cambios de estado:

Si una sustancia modifica el estado de sólido, líquido o gaseoso, se produce un cambio de estado. Un cambio de estado es una modificación en la forma en que se disponen las partículas que constituyen una sustancia.

El estado en que se encuentre un cuerpo depende de la presión a la que está sometido y de su temperatura. Para cambiar su estado se debe modificar alguna de estas variables, o ambas. Al elevar la temperatura de una sustancia sólida, aumenta la agitación de sus partículas.

5 0

2 years ago

Read 2 more answers

You are at the edge of a diving board that is 9 meters above the water. If you weigh 500 Newtons, what is your potential energy?

Semenov [28]

Answer:

4500 J

Explanation:

First, let's define some equations and derivations.

Our potential energy formula is:

$\displaystyle U = mgh$

Where <em>m </em>is mass (in kg), <em>g</em> is the gravitational constant (in m/s²), and <em>h</em> is height (in m).

We also know that <em>mg</em> is equal to the weight of an object (in N), from Newton's 2nd Law of Motion: F = ma (Force is equal to [constant] mass times acceleration).

Therefore, we can simply substitute force into the equation:

$\displaystyle U = Fh$

Where <em>F</em> is the force (in N) and <em>h</em> is still height (in m).

Now we can calculate the amount of potential energy in our system, measured in joules.

Substitute in the given variables, F = 500 N and h = 9 m:

$\displaystyle U = (500 \ N)(9 \ m)$

Using simple Pre-Algebra rules, we find that:

$\displaystyle U = 4500 \ J$

This tells us that the we have 4500 joules of potential energy when I am 9 meters above the water on the edge of the diving board.

6 0

3 years ago

Read 2 more answers