True Or False: people in the U.S. consume more liters of water than those in developing nations.

Why does a hot air balloon fall when the air inside is not heated

trapecia [35]

A hot air balloon rises in the first place because the air inside is hot, which rises. So, if the air inside is not heated, it fails to rise and falls. Warm air rises because the particles get excited and jiggle with the heat, and cause the air to take up more space. So, as the surrounding air is probably colder and denser, the less dense hot air rises up in the hot air balloon.

7 0

4 years ago

A rock is thrown from a height of 2.0 m at a window that is located 9.0 m above the ground. The initial velocity of the rock is

ELEN [110]

Answer:

The value is $x = 11.81 \ m$

Explanation:

From the question we are told that

The height is h = 2.0 m

The height of the window is $d = 9.0 \ m$

The initial velocity of the rock is $u = 20 \ m/s$

The angle at which it is thrown is $\theta = 40$

Generally the vertical component of the velocity of the stone is mathematically represented as

$v_y = 20 sin (40)$

=> $v_y = 12.86 \ m/s$

Generally the height of the window from the ground is mathematically represented as using kinematic equation as

$d = h + v_yt + \frac{1}{2} gt^2$

=> $9 = 2 +12.86 t + \frac{1}{2} * - 9.8 t^2$

Here g is negative -9.8 m/s^2 because the direction of the stone is against gravity

So

$4.9 t^2 -12.86 t + 7 =0$

Solving this quadratic equation using quadratic formula we obtain

t = 0.770 s

Generally the velocity of the stone on the x axis is mathematically represented as

$v_x = 20 * cos(40 )$

=> $v_x = 15.32 \ m/s$

Generally the distance between the person throwing the rock and the window is mathematically represented as

$x = v_x * t$

=> $x = 15.32 * 0.771$

=> $x = 11.81 \ m$

8 0

3 years ago

1.5 gigabytes equals how many terabytes?

Sav [38]

Technically it would be 0 because Terabytes are larger than gigabytes, but you're mathematical answer would be 0.0015

4 0

3 years ago

What is the frequency of highly energetic ul-

Mnenie [13.5K]

Frequency = (speed) / (wavelength)

Frequency = (3 x 10⁸ m/s) / (124 x 10⁻⁹ m)

Frequency = <em>2.42 x 10¹⁵ Hz</em>

8 0

3 years ago

A 375-g stone hangs from a thin light string that is wrapped around the circumference of a pulley with a moment of inertia of 0.

Monica [59]

Answer:

The magnitude of the acceleration of the stone is 19.87 m/s²

Explanation:

Given;

mass of stone, m = 375 g = 0.375 kg

moment of inertia, I = 0.0125 kg.m²

radius of the pulley, r = 26 cm = 0.26 m

Torque generated by the pulley on the stone is given as;

τ = F x r = Iα

where;

F is applied force on the stone due to its weight

r is the radius of the pulley

I is moment of inertia

α is angular acceleration (rad/s²)

Force, F = mg = 0.375 x 9.8 = 3.675 N

Torque, τ = F x r

τ = 3.675 x 0.26

τ = 0.9555 N.m

τ = Iα

Angular acceleration, α = τ / I

α = 0.9555 / 0.0125

α = 76.44 rad/s²

Finally, determine linear acceleration, a, in m/s²

a = αr

a = 76.44 x 0.26

a = 19.87 m/s²

Therefore, the magnitude of the acceleration of the stone is 19.87 m/s²

4 0

3 years ago