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3 years ago

Why does a partially inflated weather balloon expand as it rises?

2 answers:

5 0

Answer: So in an Inflated balloon, the pressure in the inside surface (the pressure by the gas inside the ballon) must be equal to the pressure applied on the outside surface. As the balloon rises, the outside pressure starts to decrease, so the pressure inside must decrease, this allows the surface of the balloon to grow, and the pressures can equilibrate.

Alson you can see it this way, as the outside pressure starts to decrease, there are less force holding the ballon size, then it can get a little bigger.

marusya05 [52]3 years ago

3 0

Air pressure pushing in on the balloon decreases as the balloon rises.

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What is the difference between exercise and fitness

evablogger [386]

I don't have research to back it up, but exercise is working out. Fitness is taking care of your body, that includes working out and things like eating right.

8 0

2 years ago

8. Contrast. The energy that can be released during a nuclear fission reaction with the energy that can be released during a nuc

Cloud [144]

8) the energy released by fusion is generally 3 to 4 times larger than with fission. Fission has very few by-products but fusion releases large amounts of radioactive particles because it starts with large nuclei.
9) Alpha particles are 2 protons and 2 neutrons all put together. It's really the nucleus of a helium atom. It is most dangerous if you ingest it but it can be stopped with a sheet of paper so outside the body it's not as dangerous as others and due to its size it can't get very far in the air before hitting air molecules
beta particles are high energy electrons or positrons. They travel further due to their small size but can be stopped by a thin barrier of plastic or wood.
Gamma rays are high frequency photons (light) They are stopped by metal plates and go through human tissue. They are quite dangerous.
10) The mass that is lost in chemical reactions is very small. Solve E=mc² for mass and you get m=E/c². This says the mass you lose is equal to the energy you gained divided by the speed of light squared. c² is a VERY big number so you need a lot of energy produced to notice it. Chemical reactions are simply too inefficient to get that much energy out.
11)You need high temperatures for fusion because you're trying to push two atoms together (to "fuse" them as the name suggests) The electrons in one atom repel the other electrons in the other atoms. When stripped down to only protons, you still have to overcome this repulsion (Coulomb repulsion). High temperatures means high velocity of the particles in the plasma. This gives them enough "oomph" to get close enough to fuse. Once close enough to each other, the nuclear force takes over and overwhelms the Coulomb repulsion and the nuclei fuse and release energy in doing so.

7 0

3 years ago

A small sphere is hung by a string from the ceiling of a van. When the van is stationary, the sphere hangs vertically. However,

Paraphin [41]

Answer: 42.49 $m/s^{2}$

Explanation:

To solve this, we need to keep in mind the following:

While the sphere hangs it is under the effect of gravity. It is creating a Angle of 90° taking the roof as a reference.

Gravity can be noted as a Acceleration Vector. The magnitud for Earth's Gravity is a constant: 9.81 $m/s^{2}$

The acceleration of the Van will affect the sphere also, but this accelaration will be on the X-axis and perpendicular to the gravity. Because this two vectors are taking action under the sphere they will create a angle. This angle can be measured as a relation of the two magnitudes.

Tangent (∅) = Opossite Side / Adyacent Side

By trigonometry, we know the previous formula. This formula allows us to find the Tangent of a angle as a relation between the two perpendiculars magnitudes. In this case the Opossite Side will be the Gravity Accelaration, while the Adyancent Side is the Van's Acceleration.

(1) Tangent (∅) = Gravity's Acceleration (G) / Van's Acceleration (Va)

Searching for the Va in (1)

Va = G/Tan(∅)

Where ∅ in this case is equal to 13.0°

Va = 9.81 $m/s^{2}$ / Tan(13.0°)

Va = 42.49 $m/s^{2}$

The vans acceleration need to be 42.49 $m/s^{2}$ to create an angle of 13° with the Van's Roof

3 0

3 years ago

A bird accelerating from rest at a constant rate,experiences a displacement of 28 m in 11s.What is its acceleration

Ksenya-84 [330]

Use the formula below for this question:

$v_{f} = v_{i} + 2 * a * d$

re-arrange to solve for a:

$a = \frac{v_{f} - v_{i}}{2 * d}$

now simply plug in your variables and there's your answer :). If you ever get stuck, you can look up the kinematic equations!

4 0

3 years ago

The driver of a 1750 kg car traveling on a horizontal road at 110 km/h suddenly applies the brakes. Due to a slippery pavement,

Alexeev081 [22]

Answer: a=-2.4525 m/s^2

d=s=190.3 m

Explanation:The only force that is stopping the car and causing deceleration is the frictional force Fr

Fr = 25% of weight

W=mg

W=1750*9.81

W=17167.5

Hence

$Fr=\frac{25}{100} * -17167.5\\\\Fr=-4291.875 N$

Frictional force is negative as it acts in opposite direction

According to newton second law of motion

F=ma

hence

$a=Fr/m$

$a=-4291.875/1750\\a=-2.4525$

given

u= 110 km/h

u=110*1000/3600

u=30.55 m/s

to get t we know that final velocity v=0

$v^2=u^2+2as\\0=30.55^2-2*2.4525*s\\s=190.34m$

3 0

2 years ago