Answer:
t =0.6
Explanation:
So this is just a basic kinematics where the only force acting on the ball is gravity (9.8 m/s2 [down] and air resistance is negligible.
∆d=vi∆t+1/2at2
Because you're dropping the ball, initial velocity is 0
1.5= 0*(∆t) + 1/2a*t2
After some rearranging, t= root ((2*∆d)/a) Therefore t= 0.5532833352 or root(15)/7 t=0.6s
Which of the following is a problem with the estimated age of the universe?
There are stars in our galaxy that appear to be over 15 billion years old.
The universe is shrinking, which makes it is impossible to tell how old it is.
There should be more supergiants if the universe is really about ten billion years old.
There are planets in other galaxies that are less than five billion years old.
Answer:
There are stars in our galaxy that appear to be over 15 billion years old.
Explanation:
The age of the universe is the time past since the big ban event as based on observations of the early state of the universe. The comic problem with the universe is that it's estimated to be older since the time of the big bang. It also represents a contrast with objects in the galaxies such as stars, planets that could not have been present.what are the three most common forms of energy that we use frequently
Answer:
The common forms of energy used in our houses are electrical energy, chemical energy available from fuels, food and energy originating from the sun.
Explanation:
thank me later
Answer:
power plants energy, solar energy and Water engery
what are conductors and insulators
NASA is giving serious consideration to the concept of solar sailing. A solar sailcraft uses a large, lowmass sail and the energy and momentum of sunlight for propulsion.
a. Should the sail be absorbing or reflective? Why?
b. The total power output of the sun is 3.9×10^26W. How large a sail is necessary to propel a 10,000-kg spacecraft against the gravitational force of the sun? Express your result in square kilometers.
c. Explain why your answer to part (b) is independent of the distance from the sun.
Answer:
a) the reflective surface has twice the energy transfer
b) A = 1.3 10²⁷ km²
c) the energy emitted by the sun is distributed in a sphere that depends on the square of the distance, and the gravitational force depends on the square of the distance
Explanation:
a) The pressure exerted on the candle is related to the variation of the momentum
P = [tex]\frac{1}{c} \ \frac{dp}{dt}[/tex]
in a case of absorption (inelastic shock) all the energy is absorbed therefore the pressure is
P = \frac{1}{c} \ \frac{dp}{dt}
in the case of reflection (elastic shock) an energy is absorbed by absorbing the light and then by action and reaction the same energy is absorbed in the reflected light
P = 2 \frac{1}{c} \ \frac{dp}{dt}
In conclusion, the reflective surface has twice the energy transfer.
b) pressure is defined with force per unit area
P = F / A
F = P A
this force must be greater than the gravitational force of attraction of the sun
Fg = G m Ms / r²
let's look for the case that the two forces are equal
F = Fg
P A_sail = G m Ms = r²
suppose a fully reflective sail
[tex]2 \frac{S}{c} \ A_{sail} = G \frac{m M_s}{r^2}[/tex]
The pointing vector is the power delivered per unit area
S = I = P / A
where A is the area of the sphere where the is distributed by the sun
A = 4π r²
we substitute
[tex]\frac{2P}{c} \ \frac{A_{sail}}{4 \pi r^2} = G \frac{m M_s}{r^2}[/tex]
[tex]\frac{1}{2 \pi \ c }[/tex] A_{sail} = G m M_s
A = G m M_s 2π c
let's calculate
A = 6.67 10⁻¹¹ 10000 2 10³⁰ 2π 3 10⁸
A = 1,257 10³³ m²
let's reduce to km²
A = 1.3 10³³ m² (1km / 10³ m) ²
A = 1.3 10²⁷ km²
c) The size of the candle is independent of the distance to the sun because the energy emitted by the sun is distributed in a sphere that depends on the square of the distance, and the gravitational force depends on the square of the distance, therefore the two dependencies are canceled.
A small spaceship whose mass is 1300 kg (including an astronaut) is drifting in outer space with negligible gravitational forces acting on it. If the astronaut turns on a 11 kW laser beam, what speed will the ship attain in 4.0 days because of the momentum carried away by the beam?
Answer:
Explanation:
Relation between energy and momentum is as follows .
E = h c / λ
E / c = h / λ
h /λ = momentum of a photon
momentum of a photon = E /c
= 11 x 10³ / 3 x 10⁸
= 3.67 x 10⁻⁵
In 4 days no of photon
= 4 x 24 x 60 x 60 = 345600 .
momentum of photon released
3.67 x 10⁻⁵ x 345600 .
= 12.68 kg m/s
This momentum will be imparted to spaceship .
12.68 = mv
12 .68 = 1300 x v
v = .00975 m /s
= 9.75 mm /s
Explain how newtons first law applies to the image to the left.
A block with mass M is placed on an inclined plane with slope angle q and is connected to a second hanging block with mass m by a cord passing over a small, frictionless pully. The coefficient of static friction μs and the coefficient of kinetic friction is μk. For what range values of of m will the blocks remain at rest if they are released from rest.
Answer:
The mass of the block m is:
[tex]m=M(sin(\theta)+\mu_{s}cos(\theta))[/tex]
Explanation:
Let's analyze the block by parts
For the block M
[tex]T-W_{x}-f_{f}=0[/tex] (1)
Where:
T is the tensionW(x) is the component of the weight in the x-directionF(f) is the friction force[tex]T-Mgsin(\theta)-\mu_{s}N=0[/tex]
[tex]T-Mgsin(\theta)-\mu_{s}Mgcos(\theta)=0[/tex]
For the block m
[tex]T-W=0[/tex]
[tex]T=mg[/tex] (2)
Now, let's combines equation (1) and (2):
[tex]mg-Mgsin(\theta)-\mu_{s}Mgcos(\theta)=0[/tex]
Finally, let's solve it for block m.
[tex]mg-Mg(sin(\theta)+\mu_{s}cos(\theta))=0[/tex]
[tex]m=M(sin(\theta)+\mu_{s}cos(\theta))[/tex]
I hope it helps you!
If a body of mass 2 kg is moving with a velocity of 30 m/s, then
on doubling its velocity the momentum becomes
a 30 kgm/s
b 90 kgm/s
C 120 kgm/s
d 60 kgm/s
HALPLPLPPLL
Answer:
d. 60
Explanation:
If a body of mass 2 kg is moving with a velocity of 30 m/s, then
on doubling its velocity the momentum becomes
a 30 kgm/s
b 90 kgm/s
C 120 kgm/s
d 60 kgm/s
HALPLPLPPLL
Answer:
120
Explanation:
40 points! Will give brainliest!
Which of the following describes an advantage of AC electricity over DC electricity?
A) AC is found in most low voltage operations.
B) AC is provided as strong, short bursts of electricity.
C) AC can be transported over long distances.
D) AC can be used is small electronic devices.
1. How would the forces from a header with such a light soccer ball cause a concussion? Draw
Two free body diagrams showing how the amount of peak force on the head would compare
to the amount of peak force on a soccer ball in a header that causes a collision.
Answer:
soccer when the ball hits an unprepared player in the head. He also gave examples of concussions occurring when players accidentally knock their heads into other players while attempting to head the ball, particularly if they are attempting to flick the ball backwards.
Explanation:
Heading in soccer can increase your risk of concussions. Over time, repeated subconcussive injuries can also accumulate and cause brain damage.
Imagine you could travel to the moon where the acceleration due to gravity is 1.6 m/s^2. What would be the period of
a pendulum that is 1.0 m?
Show your work.
Answer:
4.9612 s
Explanation:
Applying,
T = 2π√(L/g)............... Equation 1
Where T = period of the pendulum, L = Lenght of the pendulum, g = acceleration due to gravity of the moon, π = pie.
From the question,
Given: L = 1 m, g = 1.6 m/s²
Constant: π = 3.14
Substitute these values into equation 1
T = 2×3.14×√(1/1.6)
T = 6.28√(0.625)
T = 6.28×0.79
T = 4.9612 s
An object of mass 25kg is falling from the height h=10 m. calculate
a. The total energy of an object at h=10m.
b. Potential energy of the object when it is at h= 4m
c. Kinetic energy of the object when it is at h= 4m
d. What will be the speed of the object when it hits the ground?
Answer:
a=2500J,b=1000K,c=1000J,d=14.142m/s
Explanation:
V²=U²+2gh
V²=0 + 2×10×10=200m/s
a).kinetic energy=(1/2)mv²=(1/2)25×200=2500
potential energy=mgh
p.e=25×10×10=2500J
pe+ke=2500+2500=5KJ
b).mgh=25×10×4=1000J
c). V²=U²+2gh
V²=0+2×10×4
V²=80
kinetic energy=(1/2)mv²
=(1/2)25×80
=1KJ
d). From my first paragraph V²=200
V=√200
V=14.142m/s
What is the speed of the wave above of the frequency is 7.0 hertz
Answer:
Umm
Explanation:
In a single-slit experiment, the slit width is 150 times the wavelength of the light.
What is the width (in mm) of the central maximum on a screen 2.6 m behind the slit?
I have tried:
y=[(1+1/2)(lambda)(2.6m)] / (150lambda)
to bring me to
y=[(1.5)(2.6)] \ (150)
giving me a y value in mm of 26
HELP!
A pot fell off a shelf and took 0.60 seconds to reach the ground, with an acceleration of 9.80m/s2, due to gravity. Determine the distance it fell with the free fall formula.
Using the free fall formula for height:
H = 1/2 gt^2 ( height = 1/2 x gravity x time^2)
H = 1/2 x 9.8 x 0.6^2
H = 1.764 meters
One way to overcome gravity is
Answer:
the ultimate way to overcome the Earth's gravity is to leave the Earth's gravitational influence altogether. The force of gravity reduces in inverse proportion to the square of the distance from the centre of the Earth.
Explanation:
A bat emits a sound at a frequency of 30.0 kHz as it approaches a wall. The bat detects beats such that the frequency of the echo is 900 Hz higher than the frequency the bat is emitting. The speed of sound in air is 340 m/s at emits a sound at a frequency of 30.0 kHz
(a) What is the speed of the bat?
(b) What is the wavelength of the sound that the bat hears15?
Answer:
a) the speed of the bat is 5.02 m/s
b) the wavelength of the sound that the bat hears is 0.011 m
Explanation:
Given the data in the question;
Frequency of sound emitted by a bat f = 30.0 kHz = 30000 Hz
detected frequency by the bat δf = 900 Hz
speed of sound in air c = 340 m/s
Let speed of sound and speed of bat be c and [tex]v_s[/tex] respectively;
Now, frequency of the sound that is coming from the bat towards the wall due to DROPPLER EFFET will be;
f₁ = ( c / ( c - [tex]v_s[/tex] ) )f ----- let this be equ 1
Also, frequency does not change after deflection. The bat becomes an observer as the dropper is shifted because the reflected sound wave is coming towards it;
Hence, Doppler shifted frequency will be;
f₂ = ( (c + [tex]v_s[/tex] ) / c )f₁
from equ 1, f₁ = ( c / ( c - [tex]v_s[/tex] ) )f, so we substitute
f₂ = ( (c + [tex]v_s[/tex] ) / c ) × ( c / ( c - [tex]v_s[/tex] ) )f
f₂ = ( (c + [tex]v_s[/tex] ) / ( c - [tex]v_s[/tex] ) )f
∴ beat frequency will be;
δf = f₂ - f = ( (c + [tex]v_s[/tex] ) / ( c - [tex]v_s[/tex] ) )f - f
δf = ( 2[tex]v_s[/tex] / c - [tex]v_s[/tex] )f
δf = ( 2[tex]v_s[/tex] / c - [tex]v_s[/tex] )f
2f/δf = c - [tex]v_s[/tex] / [tex]v_s[/tex]
2f/δf = c/[tex]v_s[/tex] - [tex]v_s[/tex] / [tex]v_s[/tex]
2f/δf = c/[tex]v_s[/tex] - 1
c/[tex]v_s[/tex] = 2f/δf + 1
[tex]v_s[/tex] = c / (2f/δf + 1)
now, we substitute in our values;
[tex]v_s[/tex] = 340 / ((2×30000 / 900 ) + 1)
[tex]v_s[/tex] = 340 / (66.6666 + 1)
[tex]v_s[/tex] = 340 / 67.6666
[tex]v_s[/tex] = 5.02 m/s
Therefore, the speed of the bat is 5.02 m/s
b) the wavelength of the sound that the bat hears
frequency of reflected wave is;
f₂ = f + δf = 30000 + 900 = 30900 Hz
λ₂ = c / f₂
we substitute
λ₂ = 340 / 30900
λ₂ = 0.011 m
Therefore, the wavelength of the sound that the bat hears is 0.011 m
Based on the number on the fuse, what do you think is the maximum current allowed in this circuit?
Answer:
0.3 A
Explanation:
Build the circuit attached. Make sure the switch is turned off as you build the circuit. Set the Selected battery voltage to 10 volts.
A. Based on the number on the fuse, what do you think is the maximum current allowed in this circuit?
Solution:
A fuse is a safety device which is used in circuits for preventing very high currents which can cause overloading or start a fire. A fuse is made up of a low resistance thin piece of metal such that the flow of high current can cause the metal to melt leading to an open circuit. A fuse lets current flow up to a maximum value before it melts and the circuit will be broken.
From the image attached, since the maximum rating of the fuse is 0.3 A, hence the maximum current that can flow through the circuit is 0.3 A.
A series circuit is set up with an AA battery along with an mystery material and ammeter; however, there’s no current passing through.
A.Insulator
B.Conductor
C.Semiconductor
Answer:
A. Insulator
Explanation:
Since there is no current passing through at all.
What is gravitational force? -,-
Answer:
The force of attraction between all masses in the universe; especially the attraction of the earth's mass for bodies near its surface is called gravitational force.
When 1.5 kg of mass turns into energy, how much energy is released? Find the equation, substitution, and number with units.
Explanation:
[tex]from \: einstein \: equation : \\ E = m {c}^{2} \\ E = 1.5 \times {(3 \times {10}^{8} )}^{2} \\ E = 1.35 \times {10}^{17} \: joules[/tex]
Aluminium is produced by the reduction of aluminium oxide
What is meant by the term reduction?
Answer:
Explanation:The word reduction in terms of chemistry means loss of Oxygen,Gain of hydrogen,Gain of electrons and loss of oxidation state.
Please mark me as brainiest.
Aluminium is extracted from aluminium oxide by electrolytic reduction.
What is reduction?The process is termed as a reduction if
there is a loss of oxygen or an electronegative atom.there is a gain of hydrogen or an electropositive atom.loss of electrons.decrease in oxidation number.What is electrolytic reduction?The electrolysis method used to obtain metals from molten chloride or oxides is known as electrolytic reduction.
What is the use of electrolytic reduction?It is used in the extraction of highly electropositive metals.
To learn more about reduction and electrons here,
https://brainly.com/question/14698511
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Smoke detectors fall into two major classes. Ionization detectors, the most common units, contain two parallel electrodes that are typically separated by 3 cm with a 5-V potential difference across them. The air molecules between the electrodes are ionized by collisions with helium nuclei that are produced by a radioactive source. Most units are initially fueled with 60 million nuclei of radioactive americium 241 (half-life 430 years). The now-ionized air molecules drift toward one of the electrodes with an average speed of 0.1 m/s and thus support a small current between the two electrodes. Smoke particles that enter and combine with the ions reduce the current and initiate an alarm.
Photoelectric detectors, by contrast, contain a light-emitting diode that sends a beam of unpolarized light across a small chamber. The light beam usually has a wavelength of 6.0 × 10–7m and has an intensity of 1.0 × 10–3 W. When smoke particles enter the chamber, the light scatters in all directions. A photocell then senses either the increase in the scattered light or the reduced intensity of the light beam and sets off the alarm. The speed of light in air is 3.0 × 108 m/s.
Ionization detectors respond faster to the large smoke particles of flaming fires; photoelectric detectors sense the small particles of smoldering fires more quickly. Modern units have both types of detectors.
When fewer than 3.75 × 106 americium nuclei remain, the ionization smoke detector will not operate due to insufficient ionization. How much time will pass before there are this many nuclei remaining?
a. 1720 years
b. 2150 years
c. 4300 years
d. 6880 years
Answer:
1720 years is the amount of time that will pass.
Option a) 1720 years is the correct answer
Explanation:
Given the data in the question;
Number of nuclei initially N₀ = 60 million = 60,000,000
After time t, Number of nuclei remaining N[tex]_{rem[/tex] = 3.75 × 10⁶
Also given that; half-life of radioactive americium [tex]t_{1/2[/tex] = 430 years.
so;
λ = ln2 / [tex]t_{1/2[/tex]
we substitute
λ = ln2 / 430 years
N[tex]_{rem[/tex] = N₀e^(-λt)
solve for t
t = 1/λ × ln( N₀/N[tex]_{rem[/tex] )
so we substitute
t = 1 / (ln2 / 430 years) × ln( 60,000,000 / ( 3.75 × 10⁶ ) )
t = ( 430 years / ln2 ) × ln( 60,000,000 / ( 3.75 × 10⁶ ) )
t = ( 430 years / 0.693147 ) × ln( 16 )
t = 620.359 years × 2.7725887
t = 1720.0003 ≈ 1720 years
Therefore, 1720 years is the amount of time that will pass.
Option a) 1720 years is the correct answer
Question 1
2 pts
Explain what causes a solution to be a strong acid.
Answer:
Cuanto más fuerte es el ácido, más rápido se disocia para generar H +start superscript, plus, end superscript. Por ejemplo, el ácido clorhídrico (HCl) se disocia completamente en iones hidrógeno y cloruro cuando se mezcla con agua, por lo que se considera un ácido fuerte.
how hot can the desert get
Answer:
134 f
Explanation:
The hottest temperature ever reliably measured in a desert was 134 degrees F, in Death Valley of the Mojave Desert in 1913.
Temperature. During the day, desert temperatures rise to an average of 38°C (a little over 100°F). At night, desert temperatures fall to an average of -3.9°C (about 25°F). At night, desert temperatures fall to an average of -3.9 degrees celsius (about 25 degrees fahrenheit).
Desert surfaces receive a little more than twice the solar radiation received by humid regions and lose almost twice as much heat at night. Many mean annual temperatures range from 20-25 degrees Celsius. The extreme maximum ranges from 43.5-49 degrees Celsius. Minimum temperatures sometimes drop to -18 degrees Celsius.
5. A ball weighing 10 kg rolls 200 m down a frictionless incline with a 50 degree angle to the horizontal. If the ball’s initial velocity was 0 m/s, how much does the mechanical energy of the system change by the time the ball reaches its destination? A) It increased by 12%. B) It increases by 58%. C) It decreases by 12%. D) It does not change.
Answer:
D) It does not change
Explanation:
Since there is no friction in the inclined plane. Therefore, there is no loss in the total mechanical energy of the system. So according to the law of conservation of energy we can write:
Total Mechanical Energy at Start = Total Mechanical Energy at End + Frictional Loss
Total Mechanical Energy at Start = Total Mechanical Energy at End + 0
Total Mechanical Energy at Start = Total Mechanical Energy at End
It means there is no change in the total mechanical energy of the system.
Therefore, the correct option is:
D) It does not change
Magnesium hydroxide is a common ___?
Answer:
Hello There!!
Explanation:
The answer is=> It is a common component of antacids.
hope this helps,have a great day!!
~Pinky~
explain why the lamp does not light when the input to the transformer is directed current
Answer:
Direct current(DC) has no time varying field because current is constant as well as there is no relatively motion between coil and core(magnetic circuit) of the transformer. So there is no induced emf in secondary coil of the transformer. Tom Mounts, field engineer, and electronics technician.
Explanation:
can i have brainly if right
A 300-g chunk of ice (of density 0.900 g/cm3) is placed in a water bucket. A 20.0-g rock, with a volume of 2.00 cm3, is placed on top of the ice before water is filled to the top. When the ice melts and the rock drops to the bottom of the buckt, how much water spills out or needs to be added to maintain full level? Ignore the possible dependence of the densities of ice and water on temperature.
Answer:
18 cm³ of water
Explanation:
The correct procedure and explanation is in the picture attached. If you have any doubts, feel free to leave in the comments.
Hope this helps
Describe the formation of galaxies.
Today's cosmologists assume that matter was not uniformly distributed in the universe after the Big Bang. Dense places attract more matter than the surrounding area according to their gravitational forces. Over the course of billions of years, these gas agglomerations eventually led to the formation of the galaxies we see today.