Find the current flowing across the 20 Ω
resistor. .
35 Ω
20 Ω
15 Ω
10V

[?]Α

Please no links

Answer: 29.48 s

Explanation:

Given

The initial height of the ball is [tex]h=2.6\ m[/tex]

The ball leaves with an initial velocity of [tex]u=-20\ m/s[/tex]

Using the equation of motion

[tex]h=ut+\dfrac{1}{2}at^2\\\text{Insert the values}\\\\2.6=20\cdot t+\dfrac{1}{2}\times 9.8\times t^2\\\\\Rightarrow 9.8t^2+20t-5.2\\\\\Rightarrow t=\dfrac{-20\pm \sqrt{20^2-4\times 9.8\times (-5.2)}}{2\times 9.8}\\\\\Rightarrow t=\dfrac{-20\pm 603.84}{19.8}\\\\\Rightarrow t=29.48\ s\quad [\text{Neglecting negative t}][/tex]

Therefore, it take 29.48 s for ball to reach the ground.

The velocity of the rock just before it hits the ground is approximately 23.87m/s.

From the third equation of motion;

v² = u² + 2gs

Where u is initial velocity, v is final velocity, g is acceleration due to gravity ( g = 9.8m/s² ) and s is distance covered.

Given the data in the question;

To determine the final velocity, plug the given values into the equation of motion above.

v² = u² + 2gs

v² = ( 3.61m/s )² + ( 2 × 9.8m/s² × 28.4m )

v² = 13.0321m²/s² + 556.64m²/s²

v² = 569.6721m²/s²

v = √( 569.6721m²/s²)

v = 23.87m/s

Therefore, the final velocity of the object is 23.87m/s.

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Answer:

letter C. they are bad for the environment

Answer:

4.Given:

m=1000kg

a=(3m/s)^2

F=m×a

=1000×3

=3000N

5.Given:

m=50kg

a=(5m/s)^2

F=m×a

=50×5

=250N

6. Given

F=250N

a=(5m/s)^2

m=?

F=m×a

250N=m×(5m/s)^2

m×(5m/s)^2=250N

m=250N÷(5m/s)^2

m=50kg

Answer:

In the solar cells, the energy is obtained only during the day, when the Sun shines. .So, it increases the cost of using solar panels as the source of energy. So, the solar cell is not used to meet all our energy needs

hope this helps

have a good day :)

Explanation:

Answer:

In the solar cells, the energy is obtained only during the day, when the Sun shines. ... So, it increases the cost of using solar panels as the source of energy. So, the solar cell is not used to meet all our energy needs

Explanation:

n the solar cells, the solar panel convert solar energy into electricity, which is stored in storage battery. The storage battery give the direct current but all the appliances are working by the alternating current, so first of all direct current is converted into alternating current by any suitable appliances before it can be used to run various devices. So it increases the cost of using solar panels as the source of energy. 

Answer:

B

Explanation:

Newton's first law of motion states that every object will continue in a state of rest or uniform motion in a straight line unless a resultant force acts on it

balanced force means resultant force is 0N

this means that the speed will not change as it uniform and the direction will not change because it will continue at the same speed in a statight line and direction

sorry man, I think it was late

hope this helps

Answer:

tenis

Tenis applies to each of Newton's 3 Laws of Motion because with the first law if a tenis ball is at rest it will stay at rest unless acted on by an unbalanced force which would be playing tenis in which it would stay in motion. The second law applies since the acceleration at which it is hit times the mass equals the force it has. The third law applies since when hitting a tenis ball back and forth with racquets the reaction may be equal or opposite

Explanation:

The natural environment or natural world encompasses all living and non-living things occurring naturally, meaning in this case not artificial. The term is most often applied to the Earth or some parts of Earth

Answer:

The correct answer is - Lemon juice hydrolyzes sugar and dissolves it faster and creates a solution.

Explanation:

When mixing lemon juice and sugar in water are mixed together, the lemon juice dissolves the sugar faster as it has citric acid that hydrolyzes sucrose molecules of sugar in glucose and fructose.

This mixing of all three lemon juice, water, and sugar form a solution. Here in this solution, water is solvent, and sugar and lemon juice are solutes. The quantity of all three determined the nature of the solution if it will be acidic or more diluted.

Answer:

physical attractiveness

Explanation:

Answer:

Fossil fuels store energy from the sun as

Explanation:

Answer:

The speed decreases and the frequency remains the same.

Explanation:

Had it for a castle learning assignment, guessed and got it correct.

The speed of a light ray decreases and its frequency remains the same when it passes from glass into water.

The speed of light, also known as the velocity of light, is a fundamental constant of nature and is one of the most well-known physical quantities. It is defined as the speed at which electromagnetic radiation (light) travels through a vacuum, which has a constant value of 299,792,458 meters per second (m/s).

This speed is considered to be the fastest that anything can travel in the universe, and it is a critical component in many physical and biological processes. The speed of light is used in a wide range of scientific and technological fields, including optics, electronics, astronomy, and quantum mechanics. It is considered to be a universal constant and does not change with time, distance, or the medium through which it travels.

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Answer:

The best statement which describe this is actually:

D. Temperature decreases with altitude until the stratosphere is reached, and then it increases from there.

Explanation:

From the graph shown, it could be seen that, temperature decrease with height. The higher the height, the lower the temperature. For example, from the graph, when the height was around 50 km, the temperature was within the range of -10⁰C to 0⁰C. On the other hand, when the height increases around 78 km, the temperature decreases to the range of  to -70 ⁰C to -80⁰C

Answer:

hope you can understand the calculations

Answer:

Thus, the angle of reflection is 15 degrees.

Explanation:

Angle of incidence, i = 15 degrees

The angle of incidence is the angle between the normal to the mirror and the incident ray, the angle of reflection is the angle between the reflected ray and the normal to the mirror.

According to the laws of reflection, the angle of incidence is equal to the angle of reflection.

Thus, the angle of reflection = angle of incidence = 15 degrees

Answer:

Water ;)

Explanation:

have a great rest of your day :)

Answer:

When a ray of light, passes from a denser to a rarer medium with the angle of incidence greater than the critical angle, the ray is reflected back into the same medium. This phenomenon is call total internal reflection.

Answer:

yes

Explanation:

Reactions of acids with metals

Acids react with most metals and, when they do, a salt is produced. But unlike the reaction between acids and bases, we do not get water. Instead we get hydrogen gas.

This is the general word equation for the reaction:

metal + acid → salt + hydrogen

For example, magnesium reacts with hydrochloric acid to produce magnesium chloride:

magnesium + hydrochloric acid → magnesium chloride + hydrogen

Mg + 2HCl → MgCl2 + H2

It doesn't matter which metal or which acid is used, if there is a reaction we always get hydrogen gas as well as the salt. However, how quickly the reaction goes depends on the metal used and how high up in the reactivity series it is.

The free body diagram allows to find the results for the forces applied on the refrigerator are;

       a) Free-body diagram with applied force.

       b) Free-body diagram without applied force.

A free-body diagram is a diagram of the forces without the details of the body, these diagrams are important to clearly visualize the forces and the coordinate systems against which to take measurements.

In the attached we have a free-body diagrams for a refirerator, represented by the box where the forces are appreciated:

Newton's second law states that the net force is proportional to the mass times the acceleration of the body.

             ∑ F = ma

where F is the force, m the mass and the acceleration

          ∑ F = F - fr = 100 N

          a = 100 / m

In conclusion with the free body diagram we can find the results for the forces applied on the refrigerator are;

a) Free-body diagram with applied force.

b) Free-body diagram without applied force.

Learn more about the free-body diagram here:  brainly.com/question/16799228

Answer:

the acceleration of an object is directly pro to the net force acting on it and indirectingly proportional to its mass

Answer:

Explanation:

As given, the student has three balloons and rubs two of them on a piece of wool. The rubbing of balloon on wool is the independent variable as it was done on two and not on the third as control.

Answer:

force

Explanation:

Force is a push or a pull of an object that causes the object to speed up, slow down, or stay in one place. In other words, a force is what causes an object to move. Friction and gravity are two types of forces that influence how an object moves.

Answer:

0.909 J/gºC.

Explanation:

From the question given above, the following data were obtained:

Heat (Q) = 17000 J

Initial temperature (T₁) = 16 °C

Final temperature (T₂) = 38 °C

Mass (M) = 850 g

Specific heat capacity (C) =?

Next, we shall determine the change in the temperature of the metal. This can be obtained as follow:

Initial temperature (T₁) = 16 °C

Final temperature (T₂) = 38 °C

Change in temperature (ΔT)

ΔT = T₂ – T₁

ΔT = 38 – 16

ΔT = 22 °C

Finally, we shall determine the specific heat capacity of the metal. This can be obtained as follow:

Heat (Q) = 17000 J

Change in temperature (ΔT) = 22 °C

Mass (M) = 850 g

Specific heat capacity (C) =?

Q = MCΔT

17000 = 850 × C × 22

17000 = 18700 × C

Divide both side by 18700

C = 17000 / 18700

C = 0.909 J/gºC

Therefore, the specific heat capacity of the metal is 0.909 J/gºC.

Explanation:

The reading on the scale is

W = m(g + a)

= (77 kg)(9.8 m/s^2 + 2 m/s^2)

= 908.6 N

Answer:

58.6 m/s²

Explanation:

Applying,

s = ut+gt²/2............ equation 1

Where s = height of the rock, u = initial velocity, t = time, g = accelration due to gravity of the planet.

From the question,

Given: s = 1.55 m, t = 0.23 s, u = 0 m/s (dropped from an height)

Substitute these values into equation 1

1.55 = (0×0.23)+g(0.23²)/2

1.55 = 0.0529g/2

0.0529g = 3.1

g = 3.1/0.0529

g = 58.6 m/s²

Answer:

792J

Explanation:

Use the formula Force × Distance

With 110 newtons being the force and 7.2 meters being the distance

Which gives 792 and work us measured in joules therefore its joules

Work done is the dot product of force and displacement. The work done on the box to push across the surface for 7.2 m by applying a force of 110 N is 792 J.

Force is an external agent acting on a body tp change it from the state of motion or rest.  Force is a vector quantity thus, it is characterized by a magnitude and direction.

When force acting on a body results in displacement of the body, it is said to be work done on the body. The work done on the body is the product of force and displacement.

W = F d.

Given the force acting on the box = 110 N

 displacement d = 7.2 m

Work done w = 110 N × 7.2 m

                       = 792 J.

Therefore, the work done on the box is 792 J.

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Answer:

6, 3, 2, 5, 4, 1

Explanation:

Let's describe them from smallest to largest. In fact the size order is not exact as there are exceptions.

An asteroid is a rocky body which lies in the asteroid belt between Mars and Jupiter. They are typically quite small object. The largest asteroid Ceres has been reclassified as a dwarf planet.

A moon is typically a rocky body which is in orbit around a planet. Some moons such as our Moon are quite large and are typically bigger than asteroid. Some moons can actually be smaller than some asteroids.

A planet is a nearly spherical body which is in orbit around the Sun. Planets are larger than moons.

A star is what planets orbit around. It is the source of light and heat. Our Sun is a star which is many times bigger than all of the planets.

A solar system is a star and all of its planets, asteroids, comets and other bodies. It is significantly bigger than a star.

A galaxy, such as our Milky Way Galaxy, is a collection of solar systems orbiting around a central core. Most galaxies have a supermassive black hole at their centres.

Galaxies also form clusters which are large scale structures.

The universe is everything. It contains billions of galaxies.