I’m Sarah and I got bit by a vampire

Why can’t we see the molecules moving in a solid or liquid?

harina [27]

Answer:

Because molecules are to small for us people to see with the bare eye, unless you use a telescope.

Explanation:

5 0

3 years ago

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The state in which a star's gravitational collapse is balanced between gravity pushing inward and gas pressure pushing outward i

Andrew [12]

The relation between temperature and pressure is called the "equation of state of the gas". or "Hydrostatic equilibrium in ordinary star". Take for example a balloon, it will have a larger spherical shape, if the pressure inside exerted by the gas on a wall of a balloon balance the inward force exerted by the outside atmospheric pressure. In a dying star which is being compressed by gravity, the gas is being squeezed so the molecules is moving rapidly, resulting to a very high temperature, and this provide a balance that counteract or balances the compressive force of gravity. The very high temperature inside the star is needed to balance the force of gravity, and it is provide by "nuclear fusion energy" or else the star would collapse under the force of gravity. Depending on the size or mass of the star, it will either become, a "neutron star" or a "black hole".

5 0

3 years ago

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A constant net force that has a magnitude of 135.5 N is exerted on a 26.7 kg object that is initially not moving. a. Draw a free

jek_recluse [69]

Explanation:

Given that,

Net force = 135.5 N

Mass = 26.7 kg

(a). We need to draw a free body diagram

A force is exerted on a object.

(b). We need to calculate the acceleration

Using formula of acceleration

$a =\dfrac{F}{m}$

$a=\dfrac{135.5}{26.7}$

$a=5.07\ m/s^2$

(c). We need to draw the sketch a position vs. time graph for the object.

Using equation of motion

$s=ut+\dfrac{1}{2}at^2$

Put the value into the formula

$s=0+\dfrac{1}{2}\times5.07\times t^2$

$s=2.535 t^2$

(d). We need to draw the sketch a velocity vs. time graph for the object.

Using equation of motion

$v = u+at$

Put the value into the formula

$v=0+5.07t$

$v =5.07 t$

(e). We need to calculate the distance travel in 8.82 s

Using equation of motion

$s=ut+\dfrac{1}{2}at^2$

$s=0+\dfrac{1}{2}\times5.07\times(8.82)^2$

$s=197.20\ m$

Hence, This is the required solution.

8 0

3 years ago

Compare the maximum rate of heat transfer to the basal metabolic rate by converting a bmr of 88 kcal/hr into watts. what is the

elena-14-01-66 [18.8K]

Explanation :

It is given that,

BMR i.e basal metabolic rate is 88 kcal/hr. So, BMR in watts is converted by the following :

We know that, 1 kilocalorie = 4184 joules

So, $1\ kcal/h=\dfrac{1\times 4184\ J}{3600\ sec}$

$1\ kcal/h=1.16\ J/sec$

J/sec is nothing but watts.

So, $1\ kcal/h=1.16\ watts$

and $88\ kcal/h=88\times 1.16\ watts = 102.08\ watts$

So, it can be seen that the body can accommodate a modes amount of activity in hot weather but strenuous activity would increase the metabolic rate above the body's ability to remove heat.

8 0

4 years ago

You are climbing in the high sierra when you suddenly find yourself at the edge of a fog-shrouded cliff. to find the height of t

sergey [27]

The total time it takes the sound to reach our on top of the cliff (10.0 s) is actually sum of two times:
- the time it takes the rock to hit the ground starting from the top of the cliff, t1
- the time it takes the sound to reach the top of the cliff starting from the ground, t2
1) The rock moves by uniformly accelerated motion, with constant acceleration $g=9.81 m/s^2$ . Its law of motion is given by $y(t)=h-v_0t-\frac{1}{2}gt^2$ , where $v_0=0$ is the initial velocity of the rock, and h is the height of the cliff. The time t1 is the time at which the rock reaches the ground, so that y(t1)=0, and the equation becomes
$0=h-\frac{1}{2}gt_1^2$
2) The sound moves from the ground to the top of the cliff by uniform motion, with constant speed v=343 m/s. Therefore, the sound covers the distance h (the height of the cliff) in a time t2 given by
$h=vt_2$
3) If we rewrite h in both equations, we can write:
$=\frac{1}{2}gt_1^2=vt_2$ (1)
4) We also know that the sum of t1 and t2 is equal to 10 seconds:
$t_1+t_2=10$
from which we find
$t_2=10-t_1$
if we substitute this into eq.(1), we get
$\frac{1}{2}gt_1^2+vt_1-10v=0$
Numerically:
$4.9t_1^2 + 343 t_1 - 3430=0$
Solving the equation, we find the solution $t_1=8.87 s$ (the other solution is negative, so it does not have physical meaning). As a consequence,
$t_2 = 10-t_1 = 1.13 s$
and the height of the cliff is given by
<span> $h=vt_2=(343 m/s)(1.13 s)=388 m$ </span>

3 0

3 years ago

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