Let's say you want to start a fire using a mirror to focus sunlight. What would you do A) use a plane mirror. B) use a convex mirror , with the object to be ignited positioned at the center of curvature of the mirror. C) use a concave mirror, with the object to be ignited positioned at the center of curvature of the mirror. D) use a concave mirror, with the object to be ignited positioned halfway between the mirror and its center of curvature.

Answer:

Current, I = 20 Amperes.

Explanation:

Given the following data;

Voltage = 40 V

Resistance = 2 Ohms

To find current flowing through the resistor;

Ohm's law states that at constant temperature, the current flowing in an electrical circuit is directly proportional to the voltage applied across the two points and inversely proportional to the resistance in the electrical circuit.

Mathematically, Ohm's law is given by the formula;

[tex] V = IR[/tex]

Where;

V represents voltage measured in voltage.

I represents current measured in amperes.

R represents resistance measured in ohms.

Making current (I) the subject of formula, we have;

[tex] I = \frac {V}{R} [/tex]

Substituting into the formula, we have;

[tex] I = \frac {40}{2} [/tex]

Current, I = 20 Amperes.

Explanation:

Optics is a branch of physics that is the study of light and vision. ... The branch of physics dealing with the nature and properties of electromagnetic energy in the light spectrum and the phenomena of vision. In the broadest sense, optics deals with infrared light, visible light, and ultraviolet light.

Answer:

It spreads diseases.

Explanation:

But when cooked food is kept on the place where uncooked meat or food was kept the germs spread to the cooked food also and as the cooked food cannot be washed it harms us as we directly consume it.

Answer:

v = 6295.55 m/s

Explanation:

Given that,

The radius of a planet, [tex]r=5.32\times 10^6\ m[/tex]

The free fall acceleration of the planet, a = 7.45 m/s²

We need to find the tangential speed of a person standing at the equator.

Also, the centripetal acceleration was equal to the gravitational acceleration at the equator.

We know that,

Centri[etal acceleration,

[tex]a=\dfrac{v^2}{r}\\\\v=\sqrt{ar}\\\\v=\sqrt{5.32\times10^6\times 7.45}\\\\v=6295.55\ m/s[/tex]

So, the tangential speed of the person is equal to 6295.55 m/s.

Answer:

Prior to changes in Generation IV, all damaging Ground-type moves were physical, but ... Ground type moves will affect Flying type Pokemon when they lose their ... Gen, Move, Category, Contest, Power, Accuracy, PP, Target, Description ... at an abandoned hydroelectric plant, were giving Onix a noticeable degree of pain, ...

Missing: Precision ‎c. ‎measurement ‎d.

Explanation:

Answer:

C. Extent of a measurement and D. Ground-Type Pokemon.

Explanation:

Answer:

D: 80v is the anwser to the question

Answer:

8.829 Joules

Explanation:

The potential energy of an object, is the energy it posses (the energy stored within the object) by virtue of its relative elevation or height, position, state, or arrangement

The potential energy of an object raised to a given height, P.E. = m·g·h

Where;

m = The mass of the object

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

h = The present height of the object

For the potato sack having a mass, m = 2 kg, and raised to a height, h = 450 cm = 0.45 m, we have;

The potential energy given to the potato sack, by raising its height, P.E. is given as follows;

P.E. = 2 kg × 9.81 m/s² × 0.45 m = 8.829 Joules

The potential energy given to the potato sack, P.E. = 8.829 Joules

Answer:

What would be the path of an object thrown in the air if there was no gravity?

the answer is D

Technology makes us feel more alone because we are more dependent on social media connections than real life connections. Simply put, technology-independent architecture means not being biased towards any particular platform or software language.

Answer:

you can check out any time you like. But you don't, do you? There's one area where technology has surely encouraged a truer and more heartening personal freedom. According to Gallup, a record 42 percent of Americans now identify as politically independent.

Answer:

(D) 50 W​

Explanation:

Given the following data;

Mass = 5 kg

Force = 100 N

Distance = 60 N

Time = 2 minutes

Conversion:

1 minute = 60 seconds

2 minutes = 60 * 2 = 120 seconds

To find the power output required to push the box;

First of all, we would determine the work done in pushing the box.

Work done = force * distance

Workdone = 100 * 60

Workdone = 6000 Joules

Next, we find power output;

Power = workdone/time

Power = 6000/120

Power = 50 Watts

Answer:

12/11 Ω isvthe equivalent resistance of the circuit.

Explanation:

Answer:

eu não consigo entender essa situação o Fim dessa história só pode ter confusão dos iguais com cabeças diferentes a invés de amigas são concorrentes

Answer:

52 minutes

Explanation:

Given the following data;

Voltage = 1.5 V

Current = 2 Amperes

Energy = 9360 J

To find how many minutes will the battery last before it runs out of energy;

First of all, we would determine the power rating of the toy

Power = current * time

Power = 2 * 1.5

Power = 3 Watts

Next, we find the time;

Energy = power * time

9360 = 3 * time

Time = 9360/3

Time = 3120 seconds

To convert to minutes;

60 seconds = 1 minute

3120 seconds = 3120/60 = 52 minutes

Answer:

Explanation:

TE = KE + PE which is total energy available to a system is equal to its potential energy plus its kinetic energy, and that total energy will remain throughout the entire "trip", whatever it might be. So a is your answer.

Answer:

Explanation:

I think it's insects. All the rest have some sort of spinal structure. They are classified as vertebrates (meaning they have a spinal structure).

Answer:

Mammals

Explanation:

Mammals are the odd ones out because they do not lay eggs. Unlike amphibians, fish, birds, reptiles, and insects, which do lay eggs.

Answer:

60N

Explanation:

According to the principle of lever: a torque can control if an object will spin or not.

The torque Iskander cause is 40*1.2=48 N-m

So for balanced, Danny should cause the same torque.

48/0.8=60, Danny weigh 60N.

Answer:

the answer is already there lol

Explanation:

Answer:

answer is there you can see from there lol

Explanation:

Answer:

Answer:

hi

Explanation:

it is probably 12 m on the surface of the moon

have a good day

I hope this is help full to you

Answer:

A

Explanation:

The plate collisions that occur in these areas can produce earthquakes, volcanic activity, and crustal deformation.

hope it helps you

Answer:

[tex]E=84.5V[/tex]

Explanation:

From the question we are told that:

Number of Turns [tex]N=332turns[/tex]

Radius [tex]r= 30cm[/tex]

Field Change [tex]B=56mt-29mt=27mt[/tex]

Time [tex]t=63ms[/tex]

Generally the equation for Magnetic Field is mathematically given by

 [tex]\frac{dB}{dt}=\frac{27*10^{-3}}{29*10^{-3}}[/tex]

 [tex]\frac{dB}{dt}=0.9T/s[/tex]

Generally the Flux at 332 turns is  mathematically given by

 [tex]\phi=N*A*B[/tex]

Generally the equation for Area of coil is mathematically given by

 [tex]A=\pi*r^2[/tex]

 [tex]A=\pi*(r*10^{-2})^2[/tex]

Since

 [tex]\phi=332*\pi*(\theta*10^{-2})^2*B[/tex]

Therefore

 [tex]\frac{d \phi}{dt}=332*\pi*(900*10^{-4}*\frac{dB}{dt}[/tex]

Generally the equation for emf Magnitude is mathematically given by

 [tex]E=\frac{d\phi}{dt}[/tex]

 [tex]E=332*\pi*(900*10^{-4}*0.9[/tex]

 [tex]E=84.5V[/tex]

Answer:

Newton's first law

Explanation:

you see, when an object is in motion, it tends to stay in motion, but in your case, if a object is at rest, it usually stays at rest unless acted upon my an unbalanced force which is pulling card from under the coin extremely quick and because you pulled it extremely quick, the coin isn't light enough to be moved easily with the paper, nor enough friction and speed for the coin to continue sticking onto the piece of paper

A.K.A. the coin is heavy, which is why it did not move with the paper

Answer:

Newton's First Law - Law of Inertia

Explanation:

Newton's First Law, the Law of Inertia mentions that an object at rest will stay in rest until acted by another force. The penny's inertia will cause it to fall directly down into the cup because the magnitude of external force applied by the card will be too meager to have a notable effect.

Answer:

0.09 kg

Explanation:

The details of boiling liquid are;

The rate of thermal energy absorption by the liquid, P = 450 W

The specific latent heat of vaporization, c = 2.7 × 10⁶ J/kg

The required information = The amount of liquid vaporized in t = 9 minutes

We have;

P = E/t

Where;

P = Power supplied by the heat source = The rate of absorption of thermal energy

E = The energy absorbed

t = The time

The energy absorbed in 9 minutes, E = P × t

∴ E = 450 W × 9 min × 60 s/min = 243,000 J

The heat required to evaporate 1 kg of liquid = The  specific latent heat of vaporization, c = 2.7 × 10⁶ Joules

The mass of the liquid evaporated by the energy absorbed, E, m = E/c

∴ m = 243,000 J/(2.7 × 10⁶ J/kg) = 0.09 kg

Therefore, the mass of the liquid vaporized by the energy absorbed at a rate of 450 W, in 9 minutes, m = 0.09 kg.

Answer:

density should always be positive, you must have missed a sign somewhere

Answer:

21 m

Explanation:

Since the displacement from the door is 2 m West, we have our vector as -2i. The vector representing 14.0 m South is -14.0j. The vector representing 25.0 m East is 25.0i. The vector representing 11.0 m North is 11.0j. And, the vector representing 2.0 m West is -2.0i.

So, to get our position vector at the other location, we add all the vectors together.

So, r = -2i + (-14.0j) + 25.0i + 11.0j - 2i

= -4i + 25.0i - 14.0j + 11.0j

= 21.0i -3j m

Now, if we assume the position vector for the door is at the origin, we have r₀ = 0i + 0j m

So, our displacement from the door is r - r₀ = 21.0i - 3.0j - (0i + 0j) =  21.0i - 3.0j

So, the magnitude of the resultant displacement |r - r₀| = √(21.0² + 3.0²)

= 3.0√(7.0² + 1)

= 3.0√(49 + 1)

= 3.0√50

= 3.0 × 7.0711

= 21.2

≅ 21 m to the nearest integer