An electric circuit consists of a variable resistor connected to a source of constant potential difference. If the resistance of the resistor is doubled, the current through the resistor is
Answer:
halved.
Explanation:
Given the following data;
Potential difference = constant
Resistance = 2 * resistance = 2R
To find the current I;
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 {V}{2R} [/tex]
[tex] I = \frac {1}{2} * \frac {V}{R} [/tex]
[tex] I = \frac {1}{2} * I [/tex]
Therefore, if the resistance of the resistor is doubled, the current through the resistor is halved.
1. A 2.5 kg led projector is launched as a projectile off a tall building. At one point, as it
is flying through the air it has a velocity of 24 m/s and a height of 14 m.
a) Find the potential energy
b) Find the kinetic energy
c) Find the total mechanical energy
d) Find the potential energy at a height of 8.7 m
e) Find the kinetic energy at that same height. (Hint – the total energy is always the same
as in part c)
f) Find the velocity at that height
g) Find the velocity at a height of 11.6 m
h) At what height would the velocity be 26 m/s?
i) What is the velocity just before it smashes into the ground?
See
Answer:
Explanation:
I got everything but i. Don't know why but it's eluding me. So let's do everything but that.
a. PE = mgh so
PE = (2.5)(98)(14) and
PE = 340 J
b. [tex]KE=\frac{1}{2}mv^2[/tex] so
[tex]KE=\frac{1}{2}(2.5)(14)^2[/tex] and
KE = 250 J
c. TE = KE + PE so
TE = 340 + 250 and
TE = 590 J
d. PE at 8.7 m:
PE = (2.5)(9.8)(8.7) and
PE = 210 J
e. The KE at the same height:
TE = KE + PE and
590 = KE + 210 so
KE = 380 J
f. The velocity at that height:
[tex]380=\frac{1}{2}(2.5)v^2[/tex] and
[tex]v=\sqrt{\frac{2(380)}{2.5} }[/tex] so
v = 17 m/s
g. The velocity at a height of 11.6 m (these get a bit more involed as we move forward!). First we need to find the PE at that height and then use it in the TE equation to solve for KE, then use the value for KE in the KE equation to solve for velocity:
590 = KE + PE and
PE = (2.5)(9.8)(11.6) so
PE = 280 then
590 = KE + 280 so
KE = 310 then
[tex]310=\frac{1}{2}(2.5)v^2[/tex] and
[tex]v=\sqrt{\frac{2(310)}{2.5} }[/tex] so
v = 16 m/s
h. This one is a one-dimensional problem not using the TE. This one uses parabolic motion equations. We know that the initial velocity of this object was 0 since it started from the launcher. That allows us to find the time at which the object was at a velocity of 26 m/s. Let's do that first:
[tex]v=v_0+at[/tex] and
26 = 0 + 9.8t and
26 = 9.8t so the time at 26 m/s is
t = 2.7 seconds. Now we use that in the equation for displacement:
Δx = [tex]v_0t+\frac{1}{2}at^2[/tex] and filling in the time the object was at 26 m/s:
Δx = 0t + [tex]\frac{1}{2}(-9.8)2.7)^2[/tex] so
Δx = 36 m
i. ??? In order to find the velocity at which the object hits the ground we would need to know the initial height so we could find the time it takes to hit the ground, and then from there, sub all that in to find final velocity. In my estimations, we have 2 unknowns and I can't seem to see my way around that connundrum.
What is an impulse? (select all that apply)
J=Ft
change in momentum
V=m/a
a rash decision
Answer:
change in momentum
Explanation:
using newton's second law,
F = m ( v - u ) / t....
Ft = mv - mu
impulse is either Ft ( product of force applied and the time taken for its action )
or impulse is mv - mu ( change in momentum )
how do various factors affect climent
Answer:
The factors affecting climate are latitude, altitude, land and water distribution, distance from the sea, distance from the sun, prevailing winds and ocean currents, surface covering the land, volcanism, solar constant sunspots, wind direction and nature of mountain chains, mountain barriers.
There are six major climatic controls. They are:
Latitude: As the earth is round, sunlight does not reach everywhere equally. The temperature decreases as we move from the equator to the poles.
Altitude: As we move from the surface of the earth to the higher altitudes, the temperature decreases.
Pressure and wind system: The pressure and wind system of any area depend on the latitude and altitude of that place. Thus, it influences the temperature accordingly.
Distance from the sea: Coastal regions are cooler as compared to interior regions. As the distance from the sea increases, its influence decreases and the people experience extreme weather conditions.
Ocean currents: Cold ocean currents flowing over a region will decrease the temperature of that area whereas warm currents will increase the temperature.
Relief features: Relief features are the barriers that block currents from entering the country. High mountains act as barriers for cold or hot winds.
A scientist recorded the number of geese found in a park on various days of the week. The data are shown below. 22, 25, 29, 21, 33, 28, 28 What is the range of these data? O A. 33 O B. 7 O C. 21 O D. 12
Answer: it's 12
Explanation:
Range is the difference between the highest and lowest numbers.
33-21=12
Which resource would be the best choice to learn more information about studying martial arts?
I think videos help more than books when it comes to martial arts. You can get it on YouTu.be if your teacher doesn't teach you online, in this pandemic.
Answer:
The answer is A.) Dance studio.
Explanation:
See screenshot below
Hope this helps! :D
(Can you mark me brainliest?)
- ❤ 7272033Alt ❤
An astronaut is said to be weightless when he/she travels in a satellite. Does it mean that the earth does not attract him/her
First of all, what a weight is? weight is m × g.. and when a person is in space then the force of gravity isn't acting on him or her, so yeah it will not have weight, but remember gravity is a very very low, now if a body has more mass, more gravity will act on it right? just imagine the mass of a person and that of earth.. now yes, earth will do exert a force on the astronaut but is negiligable.
Which object would most like absorb sound?
Answer:
a blanket
Explanation:
soft materials absorb sounds meanwhile hard materials just reflect them causing an echo
kinds of solar power stations
How do you determine the specific heat of a substance?
A. Divide the enthalpy change by the change in temperature.
B.Divide the enthalpy change by the product of the mass and change in temperature.
C.Divide the change in temperature by the product of the mass and enthalpy change.
D.Divide the change in temperature by the change in enthalpy.
Answer:
I think it's A
Explanation:
I need help QUICK!! 20 points
Which of the following is/are formed as gravity pulls increasing amounts of dust and debris in a nebula together?
a. the solar wind
b. meteors
c. planetesimals
d. meteorites
describe one example of light being refracted in the living room
Answer:
television
Explanation:
a television refracts light (the light bounces off of the screen
Answer:
Suppose you have a glass slab as a paper weight, if you keep it on the paper, dont you see something strange? The paper becomes elevated in the glase slab. Everyone sees a waterbottle or glass everyday, while seeing through it, does everything seem normal? Nope. That's refraction.
Explanation:
You must have seen a prism, right? It makes light split into the visible electromagnetic spectrum.
Answer in the proper number of significant numbers
23.4 x 14
Answer:
327.6 is the answer but there is 2 sig figs in 14 so change it to 330
so 330 is the final answer
hope this helps
have a good day :)
Explanation:
The multiplication product of 23.4 × 14 is 327.6. However, there is only two significant figures in 14. So we have to take the answer in 2 significant figure. Hence, the product can be written as 3.3 × 10².
What are significant figures ?Significant figures are number of digits which can be counted as certain values associated with some uncertainties as well. There are certain rules regrading the count of significant figures in a number.
The zeros after a non-decimal number cannot be taken as significant. For eg, in 4500, there are only two significant figures. The common rule for all the arithmetic operation is that, the significant figures in the product have to be equal to the number of significant figure in the number in the operation with least significant figures.
Here, the one with least significant figures is 14. It have two significant figures. Now, product of the two numbers is :
23.4 × 14 = 327.6
But the rounded product for correct significant figure is 3.3 × 10².
Find more on significant figures:
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What occurs when light bends while passing from one medium to another?
Answer:So the answer is B
Explanation: When the light rays either bend or change their direction while passing from one medium to another it is called refraction of light. The refraction of light takes place when light travels from air into glass, from glass into air, from air into water or from water into air.
Electricity that comes into our homes from the grid is known as:
A. Static electricity
B. Resistance
C. Current electricity
D. Charge
You may have had an opportunity to skip rope or watch someone else skip rope. If you have one rope, you can skip a yourself or you can include two friends, each friend holding one end of the rope and you skipping in the middle. In this instance your friend represent notes and you were anti-node. Is it possible to skip rope with three friends with two of you in yhe middle jumping at different times?.
Answer:
What is skip rope?
Explanation:
Sorry this wont help
A man holds a rectangular card in front of and parallel to a plane mirror. In order for him to see the entire image of the card, what is the least mirror area needed ?
Answer:
mark as the brainly olss
Un objeto de 200 gramos está amarrado del extremo de una cuerda y gira describiendo un círculo horizontal de 1.20 m de radio a razón de 3 rev/seg la tensión en la cuerda es?
Answer:
La tensión es 85.3 N.
Explanation:
Cuando el objeto gira en dirección horizontal, la sumatoria de fuerzas se puede calcular usando la segunda ley de Newton:
[tex] \Sigma F_{x} =ma_{c} [/tex]
[tex] T = ma_{c} [/tex]
Dado que el movimiento es horizontal, el peso (que está en el eje y) no contribuye en la sumatoria de fuerzas en el eje x. Por lo que la única fuerza actuando sobre el objeto en la dirección del movimiento es la tensión.
En donde:
m: es la masa del objeto = 200 g = 0.200 kg
[tex]a_{c}[/tex]: es la aceleración centrípeta
La aceleración centrípeta viene dada por:
[tex]a_{c} = \omega^{2} r[/tex]
En donde:
ω: es la velocidad angular del objeto = 3 rev/s
r: es el radio = 1.20 m
Entonces, la tensión es:
[tex]T = m\omega^{2} r = 0.200 kg(3\frac{rev}{s}*\frac{2\pi rad}{1 rev})^{2}*1.20 m = 85.3 N[/tex]
Por lo tanto, la tensión es 85.3 N.
Espero que te sea de utilidad!
HELP ASAP Miguel claims that as a ball falls, it loses potential energy. Izzy claims that as a ball falls, it
gains kinetic energy. Can both students be correct? Describe the evidence which would support
either student.
Answer and Explanation:
They are both correct.
This is because potential energy is when there is potential for the object to have energy, while kinetic energy is energy that is moving already.
So, as the ball falls, it loses its potential energy, or "still/Stalled" energy, and gains kinetic energy, or moving energy.
#teamtrees #PAW (Plant And Water)
what is the definition for speed?
Explanation:
the rate at which someone or something moves or operates or is able to move or operate.
please help me I have to send for my teacher
Answer:
for the fill in the blanks
1- static
2-kinetic
3-coeffiecient
4-opposite to
5-sin theta
6-cos theta
im not sure however what to do with the top part or if its even part of what you need help with
Determine la inercia rotacional de una varilla de 4 m de largo y 2 Kg de mesa si su eje de rotación esta situado a la mitad de la varilla.
Answer:
I = 2.667 kg m²
Explanation:
The moment of inertia of a body can be calculated by the expression
I = ∫ L² dm
For high symmetry bodies the expressions of the moment of inertia are tabulated, for a rod with its axis of rotation at its midpoint it is
I = [tex]\frac{1}{12}[/tex] m L²
let's calculate
I = [tex]\frac{1}{12}[/tex] 2 4²
I = 2.667 kg m²
what happens when a sample of water turns to ice
[tex]\huge{\underline{\underline{\mathrm{\color{red}{AnswEr}}}}}[/tex]
As a sample of water turns to ice, A new molecules are formed.
order the phrases
Using the phrases in the box above, fill in the blank below to put the phrases in the correct order (# 11 - 14) Follow the arrows!
O aparelho de som do carro de João dissipa uma potência de 150W quando ligado em volume máximo. Sabendo que a bateria de seu carro fornece uma diferença de potencial de 12V, calcule a corrente máxima nesse circuito, quando esse aparelho está ligado em volume máximo e a resistência elétrica.
Answer:
i not sure
Explanation:
How many electrons are contained in 1.0 C of charge? What is the mass of the electron in 1.0C of charge?
There are approximately 6.24 x 10¹⁸ electrons contained in 1.0 C of charge. The mass of the electron in 1.0 C of charge remains the same as the mass of an electron, which is approximately 9.109 x 10⁻³¹ kg.
We may utilise the elementary charge, which represents the charge of a single electron, to calculate how many electrons are present in 1.0 C of charge. It is estimated that the elementary charge is 1.602 x 10-19 C.
Number of electrons = Charge ÷ Elementary charge
Number of electrons = 1.0 C ÷ (1.602 x 10⁻¹⁹ C)
Calculating the division:
Number of electrons ≈ 6.24 x 10¹⁸ electrons
Therefore, there are approximately 6.24 x 10¹⁸ electrons contained in 1.0 C of charge.
It is crucial to remember that the electron's mass is unaffected by the charge when considering the electron's mass in 1.0 C of charge. Regardless of the charge it carries, an electron has a mass of about 9.109 x 10⁻³¹ kg.
Thus, the mass of one electron, which is roughly 9.109 x 10⁻³¹ kg, remains constant in 1.0 C of charge.
For more details regarding electron, visit:
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The unit of area is called derived unit, why?
Answer:
Because the unit of area depends upon the other fundamental units.
Explanation:
Unit of Area = m^2
actual metre is the unit of length.
so metre × metre makes ?^2
The relationship between the equilibrant and the resultant vector is *
the equilibrant is equal in magnitude and in diredction
the equilibrant is equal in magnitude but opposite in direction
the equilibrant is different in magnitude and in direction
the equilibrant is different in magnitude but opposite in direction
Answer:
the equilibrant is equal in magnitude but opposite in direction.
Explanation:
In vector algebra, a resultant vector is a single vector that have the same effect as the effect of the net or algebraic sum of two or more vectors.
A resultant vector arises from finding the adding multiple vectors together.
When a group of vectors is replaced by a resultant vector, in order to keep the system of vectors at equilibrium, there is another vector which has the same magnitude as the resultant vector but acting in opposite direction to the resultant vector. This vector is called the equilibrant.
Part D
From this data, how many male, female, adult, and baby mountain goats do you predict are in the park?
Answer:
80
Explanation:
I literally just did this question lol I hope I helped
In an ecosystem having a park, from the given data there are 71 male,93 female, 103 adults and 61 baby goats in the park.
What is an ecosystem?Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
Learn more about ecosystem,here:
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Which of the following correctly describes how particular type of mirror reflects light? Convex mirrors reflect light to a central point (converging). Concave mirrors reflect light to a central point (converging). Concave mirrors reflect light so the light spreads out (diverging).
Answer:
Concave mirrors reflect light to a central point (converging)
Suppose the source is to the left of the mirror in question.
Parallel rays into the mirror are always reflected towards the focal point.
In the case of a concave mirror the real parallel rays pass thru the focal point.
If the mirror is convex the rays will diverge to the left and act as if they were emanating from the focal point to the right of the mirror.
