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3 years ago

Why do helium balloons float? Talk about density of atoms and compare to elements in the air.

1 answer:

7 0

The helium balloon displaces an amount of air. As long as the weight of the helium balloon fabric is lighter than the air it displaces, the balloon will float in the air. It turns out helium is a lot lighter than air.

You might be interested in

What force is needed to accelerate an object 5 m/s2 if the object has a mass of 10 kg?

Helga [31]

We know, F = m * a
F = 10 * 5
F = 50 N

In short, Your Answer would be 50 Newtons

Hope this helps!

5 0

3 years ago

Which statement bet explains the relationship between the electric force between two charged objects and the distance between th

Nataliya [291]

Coulomb's Law: Force = k x q1x q2 divided distance square
where k=9x10^9 , q1 and q2 are the charge
So if you distance is halved, your force is stronger by 4 times
and if you distance is doubled, your force is 1/4
Ask me again if you aren't clear :)

4 0

3 years ago

A small candle is 34 cm from a concave mirror having a radius of curvature of 22 cm. Where will the image of the candle be locat

xxTIMURxx [149]

Answer:

16.26 cm in front of the mirror

Explanation:

Using,

1/f = 1/u+1/v....................... Equation 1

Where f = focal focal length of the concave mirror, u = object distance, v = image distance.

make v the subject of the equation

v = fu/(u-f)................... Equation 2

Note: The focal length of a concave mirror is positive

Using the real- is- positive convention

Given: f = 22/2 = 11 cm, u = 34 cm.

Substitute into equation 2

v = (34×11)/(34-11)

v = 374/23

v = 16.26 cm.

The image will be formed 16.26 cm in front of the mirror.

5 0

2 years ago

A uniform magnetic field passes through a horizontal circular wire loop at an angle 17.3 ° 17.3° from the normal to the plane of

umka21 [38]

Answer:

4.78 × 10⁻³ T.m²

Explanation:

The expression for the magnetic flux is given by

∅ = BAcosФ

where B = magnetic field strength

A = Area of circular loop = πr²

r = radius of the wire loop

substitute πr² for A in the first equation

∅ = Bπr²cosФ

∅ = 2.55 × 3.14 × 0.025² × cos 17.3°

∅ = 4.78 × 10⁻³ T.m²

0.00478 T.m²

7 0

3 years ago

While at the county fair, you decide to ride the Ferris wheel. Having eaten too many candy apples and elephant ears, you find th

san4es73 [151]

Answer:

a. $v=3.03\frac{m}{s}$

b. $a_c=0.71\frac{m}{s^2}$

c. $\frac{W_{top}}{W}=0.93$

d. $\frac{W_{bot}}{W}=1.07$

Explanation:

a. The speed is the distance travelled divided by the time:

$v=\frac{2\pi r}{T}\\v=\frac{2\pi(13m)}{27s}\\v=3.03\frac{m}{s}$

b. The magnitud of the centripetal acceleration is given by:

$a_c=\frac{v^2}{r}\\a_c=\frac{(3.03\frac{m}{s})^2}{13m}\\a_c=0.71\frac{m}{s^2}$

c. According to Newton's second law, at the top we have:

$\sum F_{top}:W-W_{top}=ma_c\\W_{top}=mg-ma_c\\W_{top}=m(g-a_c)\\W_{top}=m(9.8\frac{m}{s^2}-0.71\frac{m}{s^2})\\W_{top}=m(9.09\frac{m}{s^2})\\\frac{W_{top}}{W}=\frac{m(9.09\frac{m}{s^2})}{m(9.8\frac{m}{s^2})}\\\frac{W_{top}}{W}=0.93$

d. According to Newton's second law, at the bottom we have:

$\sum F_{bot}:-W+W_{bot}=ma_c\\W_{bot}=mg+ma_c\\W_{bot}=m(g+a_c)\\W_{bot}=m(9.8\frac{m}{s^2}+0.71\frac{m}{s^2})\\W_{bot}=m(10.51\frac{m}{s^2})\\\frac{W_{bot}}{W}=\frac{m(10.51\frac{m}{s^2})}{m(9.8\frac{m}{s^2})}\\\frac{W_{bot}}{W}=1.07$

3 0

3 years ago