Describe the following as a (a) distance (b) speed (c) acceleration (d) force

Answer:

1. a) Astronomers use the parallax method to measure the distance to nearby stars, but

we can’t use it to measure the distance to stars in other galaxies. Why not? Why isn’t the

parallax method useful for measuring the distances to stars in other galaxies?

They are so distant that the parallax is too small to be measured since parallax varies

inversely with distance.

b) Instead of the parallax method, we use the standard candle method to measure the

distance to stars in other galaxies. In particular, we use the standard candle method to

measure the distances to Cepheid variable stars in other galaxies. What is special about

Cepheid variable stars that makes them useful for this purpose?

We can figure out their luminosities from their periods of variation. Then if we measure

their fluxes we can calculate their distances.

2. a) From what were the protons and electrons in your body made, and roughly when

were they made?

They were made from energy (or gamma rays) very soon after the big bang (in the first

second). 400,000 years later they got together to make hydrogen atoms.

b) From what were the carbon atoms in your body made, and where were they made?

They were not made in the big bang. They were made much later inside of stars or in

supernovae. They were made by fusion from lighter atoms.

3. Make two sketches of the Milky Way Galaxy, one an edge-on view and one a face-on

view, labeling the various parts of the galaxy.

You should have labeled the

Answer:

The answer is (a.) An upward force balances the downward force gravity on the skydiver

The skydiver is falling at a constant velocity because the upward force is balancing the downward force of gravity. According to Newton, the opposite force balance each other. This is stated in Newton's second law of motion.

The statement that best applies Newton’s laws of motion to explain the skydiver’s motion is that An upward force balances the downward force of gravity on the skydiver.

Newton's 3rd law often applies to skydiving.

When gravity is not acting upon the skydivers they would continue moving in the direction the vehicle they jumped from was moving.

If no air resistance takes place, then the skydivers would still accelerating at 9.8 m/s until they hit the ground.

The skydiver after leaving the aircraft will accelerates downwards due to the force of gravity

usually as there is no air resistance acting in the upwards direction, and there is a resultant force acting downwards, the skydiver will accelerates towards the ground.

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Answer:

The evaporation time gradually increased with the increase in surfactant concentration, i.e., from water to the concentration level of 0.005%. Furthermore, the evaporation time is significantly reduced, even lower than that of water containing relatively high concentrations from 0.01% to 0.1%.

Explanation:

Hi, there!!

Energy is defined as the capacity or ability to do work. It's SI unit is Joule.

here,

Joule = (kg×m×m)/(s×s)

= kg×m^2/s^2.

Therefore, the derived unit is kg.m^2 by s^2.

Hope it helps...

In a food web, the removal of any trophic level upsets the balance within the web and can cause its eventual collapse. Because producers capture solar energy and convert it to food energy, their loss would affect every other level of the food web.

The removal of the producers would cause the collapse of the entire food web. Primary consumers or herbivores, which feed on producers directly, would die off. The next to be affected would be the secondary consumers or carnivores that eat the primary consumers. Higher level consumers would suffer as organisms from lower trophic levels start to die off. Decomposers would break down the bodies of dead organisms, returning their basic elements and compounds to the environment. However, even these dead organisms would run out and the entire food web would collapse.

Hope you like the answer.

Answer: React with the skin

Explanation:

lab safety test Safety goggles and an apron must be worn when handling chemicals labeled corrosive because they React with the skin

Answer: Bleach is a base

Explanation:  If bleach had a pH level of 12, a number above 7, than it is a base.  Hope this helps!

Answer:

The momentum of an object is equal to the product of its mass and its velocity.

Explanation:

Consider an object of mass [tex]m[/tex] travelling at a velocity [tex]\vec{v}[/tex]. The momentum [tex]\vec{p}[/tex] of this object would be:

[tex]\vec{p} = m \cdot \vec{v}[/tex].

For the law of conservation of momentum, consider two objects: object [tex]\rm a[/tex] and object [tex]\rm b[/tex]. Assume that these two objects collided with each other.

The sum of the momentum of the two objects would be:

Assume that the system of these two objects is isolated. By the law of conservation of momentum, the sum of the momentum of these two objects should be the same before and after the collision. That is:

[tex]m_{\rm a}\cdot \vec{v}_{\rm a}(\text{initial}) + m_{\rm b}\cdot \vec{v}_{\rm b}(\text{initial}) = m_{\rm a}\cdot \vec{v}_{\rm a}(\text{final}) + m_{\rm b}\cdot \vec{v}_{\rm b}(\text{final})[/tex].

Answer:

38.024 KWh

Explanation

250 watts multiplied with 5 hours daily multiplied with 28 days monthly equals 35000 Watt hours. Divided by a 1000 to get the KWh equals 35 KWh.

= 250×5hrs× 28days

= 35000watts

= 35000/1000

= 35KWh

Four 6 watt lightbulbs equals 24 watts 4x6=24

Hence, 24×4.5hrs×30days

= 3024watts

= 3024/1000

= 3.024KWhr

The total amount of energy consumed in the month of February = 35 KWh + 3.024 KWh = 38.024 KWh

Note that I had to use 28days since we are considering the month of February.

Answer:

1. Tienes 1 kg de fruta.

2. Queda por recorrer 1/4 km.

3. Ambos pesan lo mismo.

Explanation:

1. Tienes 1/2 kg y cuando te doy 1/4 te queda:

[tex] m = \frac{1}{2} - \frac{1}{4} = \frac{1}{4} [/tex]

Ahora cuando te doy 3/4 kg te queda en total:

[tex] m_{T} = \frac{1}{4} + \frac{3}{4} = 1 kg [/tex]

Por lo tanto, tienes 1 kg de fruta al final.

2. Si falta por recorrer la mitad de la mitad, tenemos:

[tex] d = \frac{1/2}{2} = \frac{1}{4} [/tex]

Entonces, queda por recorrer 1/4 km.

3. El peso (P) del hierro es:

[tex] P = m*g [/tex]    

[tex] P = (1 + 1/2)kg*9.81 m/s^{2} = 14.72 N [/tex]

Y el peso de la paja es:

[tex] P = 3/2 kg*9.81 m/s^{2} = 14.72 N [/tex]

Por lo tanto, ambos pesan lo mismo.

Espero que te sea de utilidad!

Answer:

The time she takes to reach the water from when she jumps off the platform is 1.71 s

Explanation:

According to the equations of motion, we have;

v = u - g·t

v² = u² - 2·g·s

s₁ = u₁·t₁ + 1/2·g₁·t₁²

The given parameters are;

The height of the platform (assumption: above the water) = 10 m

The velocity with which she jumps, u = 3 m/s

The acceleration due to gravity, g = 9.81 m/s²

The height to which she jumps, s, is found as follows;

v² = u² - 2·g·s

At maximum height, v = 0, which gives;

0 = 3² - 2×9.81×s

2×9.81×s = 3² = 9

s = 9/(2×9.81) = 0.4587 m

s = 0.4587 m

The time to maximum height, t, is found as follows;

v = u - g·t

0 = 3 - 9.81×t

9.81×t = 3

t = 3/9.81 = 0.3058 s

The total distance, s₁ from maximum height to the water surface = s + 10 = 0.4587 + 10 = 10.4587 m = 10.46 m

The time to reach the water from maximum height, t₁, is found as follows;

s₁ = u₁·t₁ + 1/2·g₁·t₁²

Where;

s₁ =  The total distance from maximum height to the water surface = 10.46 m

u₁ = The initial velocity, this time from the maximum height = 0 m/s

g₁ = The acceleration due to gravity, g (positive this time as the diver is accelerating down) = 9.81 m/s²

t₁ = The time to reach the water from maximum height

Substituting the values gives;

s₁ = u₁·t₁ + 1/2·g₁·t₁²

10.46 = 0·t₁ + 1/2·9.81·t₁²

t₁²= 10.46/(1/2×9.81) = 2.13 s²

t₁ = √2.13  = 1.46 s

Total time = t₁ + t = 1.46 + 0.3058 = 1.7066 ≈ 1.71 s.

Therefore, the time she takes to reach the water from when she jumps off the platform = 1.71 s.

Answer:

I do not agree with the answer.

Because in reality, the atom has 2 main parts and 3 subatomic particles.

Explanation:

The parts of an atom are:

- The crust: It is the outer part of the atom and is the place where the electrons are.

- The nucleus: It is the central part of the atom and is the place that contains the protons and neutrons.

The subatomic particles of the atom are:

- Electrons: They are negatively charged particles that go in the atom's crust and are divided into specific sections.

- Protons: They are particles with a positive electric charge, the number of protons in the nucleus of an atom is what determines the atomic number of an element.

- Neutrons: They are atoms with no electric charge.

Answer:

F = 9.675Hz

Explanation:

pls for certain reasons let us make

3 loops : 6$/4 = L

6$/4 = 2

$ = 4/3 = 1.333

V = F x $

F = V/$

F = 12.9/1.333 = 9.675Hz

F = 9.675Hz

Answer:

30°

Explanation:

The angle between the normal and the vertical is the same as the angle between the incline and the horizontal.  We can show this with geometry.

Answer:

Wavelength = 1 meters

Explanation:

Given that,

Number of oscillations is 5

It passes through a point in 0.5 s

The speed of sound was recorded to be 10 m/s.

We need to find the wavelength of the sound.

Firstly, we will find frequency of this wave. Total no of oscillations per unit time is called frequency. So,

[tex]f=\dfrac{5}{0.5}\\\\f=10\ Hz[/tex]

Now the speed of wave in terms of wavelength and frequency is given by :

[tex]v=f\lambda[/tex]

Here, [tex]\lambda[/tex] = wavelength

[tex]\lambda=\dfrac{v}{f}\\\\\lambda=\dfrac{10\ m/s}{10\ Hz}\\\\\lambda=1\ m[/tex]

So, the wavelength of the sound is 1 meters.

Answer: C. when the forces acting on the object are balanced.

Answer:

c

Explanation:

Answer:

Cows,Pigs,Chicken. They are always in farm

Answer:

161,000 cm

Explanation:

1 mi × (1.61 km/mi) × (1000 m/km) × (100 cm/m) = 161,000 cm

Explanation:

Some Uses of Electromagnetic waves :

(A) Microwaves

(B) X - Rays (produced by slowing fast moving electrons)

(C) Radio Waves

Answer:

A)0.00966 N/C

B) counterclockwise direction

Explanation:

We are given;

Diameter of the metal ring; d = 4.3 cm

Radius;r = 2.15 cm = 0.021- m

Initial magnetic field, B = 1.12 T

Rate of decrease of the magnetic field;dB/dt = 0.23 T/s

Now, as a result of change in magnetic field, an emf will be induced in it. Thus, , electric field is induced and given by the formula :

∫E•dr = d/dt∫B.A •dA

This gives;

E(2πr) = dB/dt(πr²)

Gives;. 2E = dB/dt(r)

E = dB/dt × 2r

We are given;

E = 0.23 × 2(0.021)

E = 0.00966 N/C

The magnitude of the electric field induced in the ring has a magnitude of 0.00966 N/C

B) The direction of electric field will be in a counterclock wise direction when viewed by someone on the south pole of the magnet

Answer:

stationary in an electric field.

moving perpendicular to a magnetic field.

moving perpendicular to an electric field.

Explanation:

Negative charge: In physics, the term "negative charge" is defined as a phenomenon that consists of a surplus or different electrons in any field i.e magnetic or electric field.

However, the correct answer in the question above, would be:

"stationary in an electric field".

"moving perpendicular to a magnetic field".

"moving perpendicular to an electric field".

Explanation:

Given that,

Initial speed of the bus, u = 0

Acceleration of the bus, a = 0.5 m/s²

Let v is the velocity at the end of 2 minutes. The change in velocity divided by time equals acceleration.

So,

[tex]a=\dfrac{v-u}{t}\\\\v=u+at\\\\v=0+0.5\times 120\\\\v=60\ m/s[/tex]

Let d is the distance cover during that time. So,

[tex]v^2-u^2=2ad\\\\d=\dfrac{v^2-u^2}{2a}\\\\d=\dfrac{(60)^2}{2\times 0.5}\\\\d=3600\ m[/tex]

So, the final speed is 60 m/s and the distance covered during that time is 3600 m.

Answer:

The angular acceleration α = 14.7 rad/s²

Explanation:

The torque on the rod τ = Iα where I = moment of inertia of rod = mL²/12 where m =mass of rod  and L = length of rod = 4.00 m. α = angular acceleration of rod

Also, τ = Wr where W = weight of rod = mg and r = center of mass of rod = L/2.

So Iα = Wr

Substituting the value of the variables, we have

mL²α/12 = mgL/2

Simplifying by dividing through by mL, we have

mL²α/12mL = mgL/2mL

Lα/12 = g/2

multiplying both sides by 12, we have

Lα/12 × 12 = g/2 × 12

αL = 6g

α = 6g/L

α = 6 × 9.8 m/s² ÷ 4.00 m

α = 58.8 m/s² ÷ 4.00 m

α = 14.7 rad/s²

So, the angular acceleration α = 14.7 rad/s²

Answer:

Take up space

Explanation:

Actually we know this by the definition of matter which states that "matter is any substance that has mass and takes up space by having volume."

hope it helped you:)

Answer:

7.2 seconds

Explanation:

50=5

72=t, criss-cross, t=72 (5)/50

Answer:

The velocity and direction after 1 second is 8.1 m/s downwards

Explanation:

The equation of motion for an object in free fall can be written as follows;

v = u + g×t

Where;

v = The final velocity of the object

u = The initial velocity of the object = 0 m/s

g = The acceleration due to gravity = 9.81 m/s²

The velocity after one second is given by the velocity equation as follows;

v = 0 + 9.81 m/s² * 1 s = 9.81 m/s

The direction of the is downwards due to the attraction by the Earth's gravitational field which acts towards the Earth's center

Therefore, the velocity and direction after 1 second is 8.1 m/s downwards.

[tex] \huge{ \underline{ \boxed{ \bf{ \blue{Solution:}}}}}[/tex]

We will solve the above Question by using equations of motion that are:-

Here,

By using first equation of motion,

⇛ v = u + at

⇛ 10 = 15 + a(2)

⇛ -5 = 2a

Flipping it,

⇛ 2a = -5

⇛ a = -2.5 m/s² [ANSWER]

❍ Acclearation is negative because final velocity is less than Initial velocity.

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Answer:  392N

Explanation: W=mg

                 W= 40x9.8

                     = 392N

Answer:

[tex]\large \boxed{\sf 392.4 \ N}[/tex]

Explanation:

[tex]\sf Weight \ (N) =mass \ (kg) \times acceleration \ of \ gravity \ (m/s^2)[/tex]

[tex]W=mg[/tex]

[tex]W=40 \times 9.81[/tex]

[tex]W= 392.4[/tex]

Answer:

Height of pole = Height of giraffe

Explanation:

Given:

Height of giraffe = 20 ft

Height of pole = 240 inch

Find:

Which is taller

Computation:

Height of giraffe = 20 ft

We know that 1 ft = 12 inch

So,

Height of giraffe = 20 × 12 inch

Height of giraffe = 240 inch

and

Height of pole = 240 inch

Height of pole = Height of giraffe