Answer:
Δt=48 s
Explanation:
v: Barry's speed
v.: speed of the walkway
Δx=30 m
Δt1=30 s , Δt2=120 s
|Δx1|=|Δx2|
Δx=v*Δt
=> (v+v.)*30=(v-v.)*120
v=v.*5/3
30=(v+v.)*30
=> 30=(5v./3 +v.)*30
v.=3/8 m/s
v=5v./3 , v.=3/8
=> v=5/8 m/s
Δx=v*Δt
30=5/8 *Δt
Δt=48 s
A sports car moving at constant velocity travels 120m in 5.0s. If it then brakes and comes to a stop in 4.0s,what is the magnitude of it's acceleration?
✔ First calculating the speed :
V = d(in m)/t(in s)
V = 120/5 V = 24 m/s✔ You now know the average car's speed, is time it takes to stop it completely, so you can calculate its acceleration :
a = V/t
a = -24/4 a = 6 m/s² The car has an acceleration of 6 m/s².a skydiver jumped out of a plane and fell 9 miles to the ground. his average speed while falling was 174 miles/hour. how much time did the dive last?
Answer:
t = 0.051 seconds
Explanation:
Given that,
A skydiver jumped out of a plane and fell 9 miles to the ground. It means 9 miles is the distance covered.
The average speed of the skydiver is 174 miles/hour
We need to find the time for which he dive last. It means t is the time taken. Total distance covered divided by time taken is called average speed. So,
[tex]v=\dfrac{d}{t}\\\\t=\dfrac{d}{v}\\\\t=\dfrac{9}{174}\\\\t=0.051\ s[/tex]
So, a skydiver dive for 0.051 seconds.
Three books are at rest, in equilibrium, on a horizontal table as
shown. The weight of each book, which is equal to the force
gravity exerts in the downward direction, is given. What is the
net force on the middle book?
Answer:
Net force = 0
Explanation:
Short answer: if the middle book is not acceleration in any direction, the net force is zero.
Long answer: refer to the attached free-body diagram (FBD) to see why the net force is zero. Skills to draw FBD are essential in solving problems in statics.
Top book exerts -mg (downwards) on the middle book.
Middle book exerts -mg (downwards) on the bottom book.
Total downward force is -mg-mg = -2mg
By Newton's third law, when an object is not in motion, reaction equals action of -2mg in the opposite direction, therefore the reaction (upwards) is +2mg.
This makes the net force of -2mg (downwards) + 2mg (upwards) =0
On a horizontal table, three books are resting and balanced. The net force on the middle book will be equal to zero.
What is equilibrium?Equilibrium is the condition of an object when two or more opposing forces, whether internal, external or a combination of both, act on the body and cancel one another out to maintain the object in the same state as it was. The Latin term for weight or balance, libra, serves as the origin of the word equilibrium.
According to the question :
The net force is 0 if the middle book does not accelerate in any direction.
The Middle book is impacted negatively (downwards) by the top book.
The middle book pulls down on the lower book by -mg.
The total downward force is -2mg = (-mg-mg)
According to Newton's third rule, a reaction when an item is not moving equals an action of -2mg in the opposite direction, hence the reaction (upwards) is a response of +2mg.
Consequently, the net force of -2mg (downwards) + 2mg (upwards) = 0 is created.
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Janaki Temple and Pashupatinath Temple are increasing our pride how
Answer:
Janaki temple and Pashupatinath Temple are found in Nepal. These structures are religious and they increase the pride of the country through tourism. These temples are important in the country and are mostly visited by tourists.
This also helps to bring in income for the country and also helps by attracting many visitors and a corresponding development of its tourism industry.
Find the mass. 10 points. Will give brainliest.
Answer:
3.94 kgExplanation:
Given,
Force ( f ) = 30 N
Acceleration(a) = 7.6 m/s
Now, Let's find the mass of the ball
Using the Newton's second law of motion:
We get:
[tex]force \: = mass \: \times acceleration[/tex]
plug the value
[tex]30 \: = m \: \times 7.6[/tex]
Use the commutative property to reorder the terms
[tex] 30 = 7.6 \: m[/tex]
Swap the sides of the equation
[tex]7.6m = 30[/tex]
Divide both sides of the equation by 7.6
[tex] \frac{7.6 \: m}{7.6} = \frac{30}{7.6} [/tex]
Calculate
[tex]m = 3.94 \: kg[/tex]
Hope this helps..
Best regards!!
Answer:
[tex]\displaystyle \boxed{\mathrm{3.95 \: kg }}[/tex]
Explanation:
[tex]\mathrm{force \: (N) = mass \: (kg) \times acceleration \: (m/s^2)}[/tex]
[tex]\mathrm{force = 30N}[/tex]
[tex]\mathrm{acceleration = 7.6 \: m/s^2 }[/tex]
[tex]\mathrm{Find \: the \: mass.}[/tex]
[tex]\mathrm{30 = m \times 7.6}[/tex]
[tex]\displaystyle \mathrm{m =\frac{30}{7.6} }[/tex]
[tex]\displaystyle \mathrm{m = 3.947... }[/tex]
formula of minimmum pressure
Answer:
pressure=force/area
A uniform string of length 10.0 m and weight 0.32 N is attached to the ceiling. A weight of 1.00 kN hangs from its lower end. The lower end of the string is suddenly displaced horizontally. How long does it take the resulting wave pulse to travel to the upper end
Answer: 0.0180701 s
Explanation:
Given the following :
Length of string (L) = 10 m
Weight of string (W) = 0.32 N
Weight attached to lower end = 1kN = 1×10^3
Using the relation:
Time (t) = √ (weight of string * Length) / weight attached to lower end * acceleration due to gravity
g = acceleration due to gravity = 9.8m/s^2
Weight of string = 0.32N
Time(t) = √ (0.32 * 10) / [(1*10^3) * (9.8)]
Time = √3.2 / 9800
= √0.0003265
= 0.0180701s
8. You have two iron rods which are identical in appearance, but one is a permanent magnet and the other is unmagnetized. What series of simple experiments can you perform, using only the two rods, which will allow you to determine which of the rods is the permanent magnet
Answer:
Explanation: Let assume that bars are labeled A and B
Method 1
Using just the identical appearing bar magnet and unmagnetized iron bar.
Place the end of bar A in the middle of bar B.
If bar A sticks to bar B, then bar A is the magnet and bar B the umagnetized iron bar.
If bar A jumps to one of the ends of bar B, then bar B is the magnet.
Reason been that the magnetic field on a bar magnet is greatest at the two poles where the field comes out of the magnet. The center, between the poles, will be the weakest part of the field.
Method 2
Another solution would be to separate the two by quite some distance, float them on a piece of cork/wood in a plastic bucket or suspend them from long strings, then see which one consistently (eventually) lines up tending towards the Earth’s magnetic field.
We have seen that starlight passing through the interstellar medium is dimmed and reddened. Look at the photo of a sunset on Earth. The Sun’s light also appears reddish at sunset. Given your understanding of the reddening of starlight, why do you think sunsets appear red?
Answer:
Explanation:
Reddening of sun's rays at sunset and sunrise is due to scattering of light . The white light consisting of seven colours coming from the sun are scattered in different directions when they fall on the air particles present in atmosphere . Red coloured light scatters least and it travels straight forward to the viewer on the earth . On the other hand other colours scatter most and therefore they go out of area of vision for the viewer on the earth . Since only red colour reaches the eye of the viewer , sun's ray appear red . This happens during sunrise and sunset . It is so because during this period , sun rays travel far greater distance through atmosphere , so scattering is most pronounced .
What happens when white light shines through a translucent, red, glass window? a) All colors of light except red are transmitted through the glass. b) Red light is transmitted through and reflected by the glass c) Red light is absorbed by the glass d) all colors except red are reflected by the glass
Answer:
b. Red light is transmitted through and reflected by the glass
Explanation:
Give me brainliest plz!
All of the wavelengths of the red light are absorbed when it passes through a translucent red glass window, but the red light is transmitted and reflected.
What happens when white light shines through red glass?Red light emerges from the other side of a white light source that has been passed through a red filter. This is so that only red light can pass through the red filter. The spectrum's other colors (wavelengths) are absorbed. Similar to this, a green filter only lets through green light.White light is colorless light that contains all the wavelengths of the visible spectrum. Only specific wavelengths of white light are filtered through transparent or translucent things.Through a colorful glass, white light shines through. Except for the color it is shining through, all light wavelengths are absorbed by the glass.Therefore, if the red light passes through a translucent, red, glass, window, all the wavelengths are absorbed but the red light is transmitted and reflected.
Therefore, the correct answer is option b) Red light is transmitted through and reflected by the glass.
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A wire carrying a 35.0 A current passes between the poles of a strong magnet such that the wire is perpendicular to the magnet's field, and there is a 2.55 N force on the 3.00 cm of wire in the field. What is the average field strength (in T) between the poles of the magnet
Answer:
7.65 T
Explanation:
From the question,
Using,
F = BILsinФ......................... Equation 1
Where F = Force, B = magnetic field strength, I = current, L = Length, Ф = Angle.
Make B the subject of the equation
B = F/ILsinФ........................Equation 2
Given: F = 2.55 N, I = 32 A, L = 3.00 cm = 0.03 m, Ф = 90° (perpendicular)
Substitute into equation 2
B = 2.55/(32×0.03×sin90°)
B = 2.55/0.96
B = 7.65 T
Law of conservation
of momentum
Answer:
Explanation:
Law of conservation of momentum is applied in solving collision problem. When two body collides, their momentum after collision can be determined using the law.
The law States that the sum of momentum of two bodies before collision is equal to the sum of their momentum after collision. Before collision, both bodies moves with a different velocity while during some cases, the bodies moves with a common velocity after collision.
Whether they move with or without the same velocity depends on the type of collision that exists between them after the collision. After collision, some object sticks together and move with a common velocity while some doesn't.
If the bodies sticks together after collision, the type of collision that occur is inelastic (energy is not conserved) and if they splits after collision, the type of collision that occur is an elastic collision (energy is conserved).
Let m1 and m2 be the masses of the bodies
u1 and u2 be their velocities before collision
v1 and v2 be their velocities after collision.
According to the law;
m1u1 + m2u2 = m1v1 + m2v2
Note that momentum = mass × velocity of the body.
Question 1 of 10
What is a neutron
A. A particle inside the nucleus that has no charge
B. A positive particle inside the nucleus
O C. A negative particle outside the nucleus
O D. A negative particle inside the nucleus
Answer:
The neutron is a subatomic particle, symbol
n
or
n0
, with no electric charge and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behave similarly within the nucleus, and each has a mass of approximately one atomic mass unit, they are both referred to as nucleons.[6] Their properties and interactions are described by nuclear physics.
Explanation:
pls mark me as BRAINLIEST
By starting with a falsifiable hypothesis and proceeding to gather data and ensure replicability, a scientist can contribute to the potential formation of a(n)
Answer:
theory
Explanation:
A scientist can contribute to the formation of a theory in a particular subject by conducting research along the line of that subject.
Conducting research requires the formation of a hypothesis and testing the hypothesis by conducting a relevant experiment during which data are gathered, analyzed, and interpreted in order to falsify or accept the hypothesis.
A good experiment must be replicate-able. When the same experiment is repeated by different independent researchers and the same conclusion is arrived at, this could potentially lead to the formation of a theory.
Hence, a scientist can contribute to the formation of a theory by conducting an experiment with replicability in order to test a hypothesis.
A car engine burns gas at 495 K and exhausts to the air at 293 K. What is the highest possible efficiency it could have?
(NO UNIT)
Answer:
59.19%
Explanation:
Step 1:
Data obtained from the question. This include the following:
Input temperature = 495 K.
Output temperature = 293 K.
Efficiency =..?
Step 2:
Determination of the efficiency of the engine.
Efficiency is simply defined as the ratio of output to input times 100. Mathematically, it is expressed as:
Efficiency = output /input x 100
With the above formula, we can calculate the efficiency of the engine as follow:
Input temperature = 495 K.
Output temperature = 293 K.
Efficiency =..?
Efficiency = output /input x 100
Efficiency = 293/495 x 100
Efficiency = 59.19%
Therefore, the efficiency of the engine is 59.19%
Answer:
0.41
Explanation:
Trust me bro
Calculating heat gained, need help!!!
Q=(m)(c)(triangle T)
trial 1:
Q=(0.4)(4.186 J/kg)(78)=?
trial 2:
Q=(0.6)(4.186 J/kg)(78)=?
trial 3:
Q=(0.45)(4.186 J/kg)(75)=?
Explanation:
q = mCΔT
where m is mass,
C is specific heat capacity,
and ΔT is change in temperature.
Make sure all your units match. Assuming the substance is water, C = 4186 J/kg/°C.
Trial 1:
q = (0.4 kg) (4186 J/kg/°C) (78°C)
q = 130,600 J
Trial 2:
q = (0.6 kg) (4186 J/kg/°C) (78°C)
q = 195,900 J
Trial 3:
q = (0.45 kg) (4186 J/kg/°C) (75°C)
q = 141,300 J
Velocity is a description of an object’s blank
Velocity is the description of an object's motion from one point to another.
It tells the speed with which the trip is completed, and the direction from the start-point to the end-point. It tells nothing about any twists, turns, loops, bends, or stops along the way.
Which statement describes one feature of a closed circuit? Charges do not flow. Bulbs will not shine. The circuit is broken. The circuit is complete.
I inferred you've referring to a close electrical circuit.
Answer:
The circuit is complete.
Explanation:
A closed electrical circuit is indeed a complete circuit. Also, it allows charges to flow, the bulbs in the circuit will shine and it is not broken.
It is termed closed circuit because there is no brokage in the series of electrical wires or the switch; which may prevent the free flow of current or charges. Thus, a feature that marks closed circuits is that they are complete.
Answer:
The circuit is complete.
Explanation:
HELP me pleaseeee somebody
an object is placed 30cm from a mirror of focal length 15 cm the object is 7.5cm tall. where is the image located? how tall is the image??
Explanation:
It is given that,
Object distance from the mirror, u = -30 cm
Focal length of the mirror, f = +15 cm
Size of the object, h = 7.5 cm
We need to find the image distance and the size of the image.
Mirror's formula, [tex]\dfrac{1}{v}+\dfrac{1}{u}=\dfrac{1}{f}[/tex]
v is image distance
[tex]\dfrac{1}{v}=\dfrac{1}{f}-\dfrac{1}{u}\\\\\dfrac{1}{v}=\dfrac{1}{(15)}-\dfrac{1}{(-30)}\\\\v=10\ cm[/tex]
Let h' is the size of the image. So,
[tex]\dfrac{h'}{h}=\dfrac{-v}{u}\\\\h'=\dfrac{-vh}{u}\\\\h'=\dfrac{-10\times 7.5}{-30}\\\\h'=2.5\ cm[/tex]
So, the image is located at a distance of 10 cm and the size of the image is 2.5 cm.
1. Analogies exist between rotational and translational physical quantities. Identify the rotational term analogous to each of the following: acceleration, force, mass, work, translational kinetic energy, linear momentum, impulse.
2. Explain why centripetal acceleration changes the direction of velocity in circular motion but not its magnitude.
Answer:
1) a α, m I, W=F.d W =τ . θ,
2) a = v²/r
Explanation:
1) The amounts of rotational and translational motion are related
acceleration is
a = d²x / dt²
linear displacement is equivalent to angular rotation, therefore angular acceleration is
α = d²θ / dt²
force in linear motion is equivalent to moment in endowment motion
F = m a
τ = I α
the mass is the inertia of the translation, in rotational motion the moment of inertia is the rotational inertia
I = m r²
Work is defined by W = F. d
in rotation it is defined by W = τ . θ
The linear momentum is p = mv
the angular momentum L = I w
momentum the linear motion is I = F dt
in the rotation it is I = τ dt
2) The velocity is a vector therefore it has modulus and direction, linear acceleration changes the modulus of velocity, whereas circular motion changes the direction (the other element of the vector).
[tex]a_{c}[/tex]Ac = v²/r
Which of the following object is in dynamic equilibrium?
Answer:
A car driving in a straight line 20 m/s
Explanation:
ayepecks silly
Which is the best example of muscular endurance
Answer:
personally I'd say C by do not know if that is the exact answer
Imagine that your standing on a beach but cannot swim. Your friend encourages you to walk into the surf zone created by incoming deep-water waves that have a wavelength of 30 meters. Would it be safe to walk out to where the waves are breaking? Explain how you arrived at your answer.
Answer:
It would not be safe to walk out to where waves are breaking due to the effect of rip currents
Explanation:
The water depth in the surf zone is between 5 to 10 meters deep and with a wavelength of 30 meters, the speed of the wave is considerably fast such that control for safety may be difficult
Also the speed of the wave is directly related to the depth of the water which means that where the wave described above is fast as well as the rip current, also the water depth is expected to be considerable for a non swimmer
It is best to seek for sign post regarding safe areas and do not go into the water where there are no lifeguards or marked safe zones.
It won't be safe to walk out to where the waves are breaking.
This is because the wavelength is 30 meters which is a characteristic of
areas with significant water depth in the range of 5-11 meters.Under these
conditions the waves are usually very fast and may get swept with the
current from the water waves when trying to run from it.
It is recommended that we stay in areas where the depth is noted as not
being much and should always seek help and clarity from the life guards so
as to prevent drowning and death.
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Ozone molecules in the stratosphere absorb much of the harmful radiation from the sun. How many ozone molecules are present in 2.00 L of air under the stratospheric ozone conditions of 275 K temperature and 1.89 × 10−3 atm pressure?
Answer:
1.01×10^20 molecules of ozone.
Explanation:
Data obtained from the question include:
Volume (V) = 2 L
Temperature (T) = 275 K
Pressure (P) = 1.89×10¯³ atm
Gas constant (R) = 0.0821 atm.L/Kmol
Number of mole (n) of ozone =.?
Using the ideal gas equation, we can obtain the number of mole of ozone as follow:
PV = nRT
1.89×10¯³ x 2 = n x 0.0821 x 275
Divide both side by 0.0821 x 275
n = (1.89×10¯³ x 2) /(0.0821 x 275)
n = 1.67×10¯⁴ mole.
Therefore the number of mole of ozone in 2 L of air is 1.67×10¯⁴ mole.
Finally, we shall determine the number of molecules present in 1.67×10¯⁴ mole of ozone.
This can be obtained as follow:
From Avogadro's hypothesis, 1 mole of any substance contains 6.02×10²³ molecules. This implies that 1 mole of ozone contains 6.02×10²³ molecules.
If 1 mole of ozone contains 6.02×10²³ molecules,
therefore, 1.67×10¯⁴ mole of ozone will contain = 1.67×10¯⁴ x 6.02×10²³ = 1.01×10^20 molecules.
Therefore, 1.01×10^20 molecules of ozone are present in 2 L of air.
The density of water is 1000 kg m^3. What is the value expressed in gcm^-3 units? please help me..
(1) 1000 (2) 100 (3) 1 (4) 0.1 (5) 0.01
Here's the neat, cool way to convert units like this:
-- 1 kilogram = 1,000 grams
-- 1 meter = 100 centimeters
So . . . . .
(1000 kg/m³) x (1000 g/kg) x (1 m/100 cm)³ =
(1,000 kg/m³) x (1,000 g/kg) x (1 m³/1,000,000 cm³) =
(1,000 x 1,000 x 1 / 1,000,000) (kg-g-m³ / m³-kg-cm³) = 1 g/cm³
You and a friend are on a swing set and her swing is slightly longer than yours. If you both start swinging at the same time, from the same height, where will she be after you have completed one complete swing back and forth?
a. She will still be at the same height as you.
b. She will be slightly higher than you.
c. She will be slightly lower than you but moving downward away from you.
d. She will be slightly lower than you but moving upward toward you.
Answer:
d. She will be slightly lower than you but moving upward toward you.
Explanation:
Since your swing is slightly shorter than your friend's swing, then you will have more angular speed than your friend. Angular speed increases with a decrease in radius. The closer the body is to the center, the faster the body swings. By the time you would have completed one complete swing back and forth, your friend will just be moving towards you, and she will be slightly lower than you but moving upwards towards you. This principle is the same reason gymnasts pull their limbs closer to their body when they need to swing faster.
Can someone please help me?
An alien spaceship is 650 m above the ground and moving at a constant velocity of 175 m/s upwards.
How high above the ground is the ship after 5 seconds?
Answer:
1525 meters above ground
Explanation:
So to do this you will need to write this in slope intercept form or [tex]y=mx+b[/tex]. So 650 would be the b, 175 would be the m, and the x would be 5 so the equation would be [tex]y=175(5)+650[/tex] so if you solve or simplify the equation you will get 1525 meters above the ground and that would be our final answer.
How does increasing frequency affect the crests of a wave?
They get higher.
They get closer together.
They get lower.
They get farther apart.
Answer:
they get closer together
Explanation:
Which reverses the flow of current through
an electric motor?
Answer:
a commutator
Explanation:
A carpenter measured the lengeth of a small piece of timber as 24.6cm .Calculate the relative error in the measurement if the true length is 24.5cm
ANSWER:
0.4081%
Explanation:
Difference=24.6-24.5=0.1
Relative error = 0.1/24.5*100=0.4081%
Relative error is equal to the = difference between both the values/The true value *100