Answer: D
Explanation:
Given that a car travels from point A to B in 3 hours and returns back to point A in 5 hours. Points A and B are 150 miles apart along a straight highway.
From point A to B
The speed = distance / time
Where
Distance = 150 mile
Time = 3 hours
Substitute the values into the formula
Speed = 150/3 = 50 mile/ hours
From Point B to Point A
Distance = 150 miles
Time = 5 hours
Where speed = distance/ time
substitute all the parameters into the formula
Speed = 150/5 = 30 mph
Therefore, The car travels at 50 mph for the first half and 30 mph for the second half.
The correct answer is option D
Pls help promise to mark as brainlist
Answer:
The answers to your questions are given below
Explanation:
A. Definition of momentum.
Momentum of an object can be defined as the product of the mass of the object and its velocity. Mathematically, it expreessed as:
Momentum = mass x Velocity
From the above equation, we can derive the SI unit of momentum as follow:
Mass is measured in Kilogram (Kg)
Velocity is measured in meter per second (ms¯¹).
Momentum = mass x Velocity
Momentum = Kg x ms¯¹
Momentum = Kg•ms¯¹
Therefore, the SI unit of momentum is Kg•ms¯¹.
Bi. Determination of the force of the body from O to A.
Mass (m) = 5 kg
Velocity (v) = 40 ms¯¹
Time (t) = 2 secs.
Force (F) =?
Next, we shall determine the acceleration of the body.
Acceleration (a) = Velocity (v) /Time (t)
a = v /t
Velocity (v) = 40 ms¯¹
Time (t) = 2 secs.
Acceleration (a) =.?
a = v/t
a = 40/2
a = 20 ms¯²
Now, we can obtain the force as follow:
Mass (m) = 5 kg
Acceleration (a) = 20 ms¯²
Force (F) =?
Force (F) = mass (m) x Acceleration (a)
F = ma
F = 5 x 20
F = 100 N
Therefore, the force of the body from O to A is 100 N.
Bii. Determination of the force of the body from B to C.
Mass (m) = 5 kg
Velocity (v) = 40 ms¯¹
Time (t) = 10 – 6 = 4 secs.
Force (F) =?
Next, we shall determine the acceleration of the body.
Acceleration (a) = Velocity (v) /Time (t)
a = v /t
Velocity (v) = 40 ms¯¹
Time (t) = 4 secs.
Acceleration (a) =.?
a = v/t
a = 40/4
a = 10 ms¯²
Now, we can obtain the force as follow:
Mass (m) = 5 kg
Acceleration (a) = 10 ms¯²
Force (F) =?
Force (F) = mass (m) x Acceleration (a)
F = ma
F = 5 x 10
F = 50 N
Therefore, the force of the body from B to C is 50 N.
The probe used in a medical ultrasound examination emits sound waves in air that have a wavelength of 0.12 mm. What is the wavelength of the sound waves in the patient?a) 0.54 mm b) 0.12 mm c) 0.26 mm d) 0.027 mm
Answer:
0.54mm
Explanation:
Given the following :
Wavelength (λ) of Soundwave in air = 0.12mm
Velocity of sound wave (v) = 340m/s
Calculate the frequency (f) :
v = fλ
Wavelength to metres
1000mm = 1 m
0.12mm = (0.12/1000)m
= 0.00012m
v = fλ
340 = F * 0.00012
f = 340 / 0.00012
f = 2833333.3 Hz
Wavelength of Soundwave in the patient:
Velocity of sound wave through body tissue = 1540m/s
Therefore,
Using v = fλ
λ = v / f
λ = 1540 / 2833333.3
λ = 0.0005435m
λ = (0.0005435 * 1000)mm
λ = 0.5435mm = 0.54mm
The distance between neighbouring, identical wave components, such as adjacent compressions, determines a sound's wavelength. The number of waves passing a spot in a given amount of time is known as the frequency, which is the same as the source's frequency.
What wavelength of the sound waves in the patient?Wavelength (λ) of Soundwave in air = 0.12 mm
Velocity of sound wave (v) = 340m/s
Calculate the frequency (f) :
v = fλ
Wavelength to metres
1000 mm = 1 m
0.12 mm = (0.12/1000)m
= 0.00012 m
v = fλ
340 = F × 0.00012
f = 340 / 0.00012
f = 2833333.3 Hz
Wavelength of Soundwave in the patient:
Sound waves travel through body tissue at a speed of 1540 m/s.
Therefore, Using v = fλ
λ = v / f
λ = 1540 / 2833333.3
λ = 0.0005435m
λ = (0.0005435 × 1000)mm
λ = 0.5435mm = 0.54 mm
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3) An earth moving machine uses diesel oil, which when burnt will produce 3.0x10 9 J of energy. The work performed by the machine is 2.7x 10 8 J. What is the efficiency of the machine?
Answer:
The answer is below
Explanation:
The efficiency of a machine is the ratio of its output to its input. The efficiency shows how effective the machine by the way it converts the input energy into work. The higher the efficiency of the machine the more effective it is. The efficiency is usually less than 1.
Given that the machine uses diesel oil (input) that can produce 3.0 x 10⁹ J of energy while the work performed by the machine (output) is 2.7 x 10⁸ J. The efficiency is given as:
Efficiency = output / input = 2.7 x 10⁸ J / 3.0 x 10⁹ J = 0.09 = 9%
This means that the machine is not effective because of its low efficiency
help please, last ride guys
Answer:
Solution ( for fourth attachment ) : 38°C
Tip : Remember the units °C when submitting answer
Explanation:
As you mentioned, we only need the solution for the fourth attachment.
The idea here is that the heat lost by the metal will be equal to the heat gained by the water. We know that the specific heat gained or lost will always be represented by the following formula,
q = m [tex]*[/tex] c
Therefore if we substitute the know values and equate the two equations knowing that " q " is common among them --- ( 1 )
0.33 [tex]*[/tex] 448
Remember that the change in temperature of iron (ΔT) would be represented by final temperature - initial temperature, or final temperature - 693. Similarly the change in temperature of water will be final temperature - 39. Now we can pose the final temperature as a, and solve for a through substitution --- ( 2 )
0.33 [tex]*[/tex] 448
From here on take a look at the attachment. It represents how to receive get a through simple algebra. Here a, the final temperature, is about 38°C. In exact terms it will be [tex]38.03617\dots[/tex]°C.
Imagine you re in an entrepreneur and have been provided a loan by a bank to set up a small electro plating unit. What would you like to electorate and for what purpose?
Answer:
Electroplating involves deposition of a thin layer of metal onto the surface of a substance(compound) through electric current. This helps preserve the substance(compound) from rust and oxidative damage.
As an entrepreneur which has been provided a loan by a bank to set up a small electro plating unit. I would venture into electroplating electronic/electric appliances parts.This is because these types of appliances are in vogue now and used my millions of people for their day to day activities. This means that more people will come for various degrees of production and repairs which would include electroplating . This translates to more customers and more money for the repayment of the loan.
You need to repair a broken fence in your yard. The hole in your fence is around 3 meters in length and for whatever reason, the store you go to has oddly specific width 20cm wood. Each plank of wood costs $16.20, how much will it cost to repair your fence?
The correct answer is $243
Explanation:
The hole in the fence is 3 meters, this means it is necessary to buy wood that covers this distance. Now, each meter is equal to 100 centimeters, this means 3 meters is equivalent to 300 centimeters ( 100 cm in each meter x 3). Besides this, it is known each plank covers 20cm and costs $16.20. In this context, the next step is to find how many planks are needed. The process is shown below:
300 cm (total width) ÷ 20 cm (width of 1 plank) = 15 planks
This means 15 planks are needed. Finally, fin the total cost
15 planks x $16.20 (cost of 1 plan) = $243
What is the atomic number of hydrogen? A. 26 B. 14 C.35 D. 1
Answer:
1
Explanation:
Hydrogen is the first element in the periodic table so its atomic number is 1.
What is the function of a heart rate monitor?
O to monitor blood pressure
O to track abnormal heart rhythm
O to estimate VO2max
O to track how fast a heart beats
Answer:
O- to track how fast a heart beats
Explanation:
What are the chances that radio transmissions from Earth or messages sent on distant space probes will ever be received by living beings
Answer:
Very low
Explanation:
It is fair to say to a reasonable extent that there are very low chances that radio transmissions from Earth or messages sent on distant space probes will ever be received by living beings .
Bear in mind that for years some scientists have believed without any substantial evidence that there are other living beings in distant space.
Hi please may someone help me especially on the sketch part.
An object falls from a hovering helicopter and hits the ground at a speed of 30 m/s. How long does it take the object to reach the ground and how far does it fall? Sketch a velocity-time graph for the object (ignore air resistance).
Ignoring the air resistance it will take about 3 seconds for the object to reach the ground.We know that the acceleration due to gravity is 10m/s2.
We also know that the final velocity is 30 m/s while the initial velocity is 0 m/s
we can use the formulae for acceleration to calculate the time taken/
(final - initial velocity)/timetaken=10
(30-0)/timetaken=10
timetaken =30/10=3 seconds
Seje
A burning electric bulb is a good example of a(an)... object.
2 points
illuminated
luminous
translucent
transparent
Clear selection
Can you help me answer this pls
Answer:
luminous bcz they emits light by their own and don't need other resources to emit light
A bus is travelling at 10m/s. It accelerates at 2m/s^2 over a distance of 20m. Calculate it's final velocity
Answer:
13.4 m/s
Explanation:
Given:
Δx = 20 m
v₀ = 10 m/s
a = 2 m/s²
Find: v
v² = v₀² + 2aΔx
v² = (10 m/s)² + 2 (2 m/s²) (20 m)
v = 13.4 m/s
Will mark as BRAINLIEST.....
A balloon is ascending at the rate of 4.9 m/s. A packet is dropped from from the balloon when situated at a height of 100m.
How long does it take the packet to reach the ground ?
What is it's final velocity ?
Answer:
Explanation:
Initially the packet was ascending up with the balloon.
Taking upward as positive direction;
initial velocity, u = 4.9 m/s
final velocity = v m/s
initial height, h₁ = 100 m
final height, h₂ = 0
a = -9.8 m/s²
time taken = t seconds
Considering the second equation of motion.
S = ut + 1/2at^2
s = ut + 0.5at²
(h₂-h₁) = ut + 0.5at²
0- 100 = 4.9t + 0.5×(-9.8)×t²
-100 = 4.9t - 4.9t²
4.9t² -4.9t - 100 =0
t² -t - 20.41 = 0
Using : b±√(b²-4ac))/(2a).... 1
Where a =1, b = -1 c =-20.408
Substituting the values into equation 1
Solving it, we get t = 5.045s
v = u + at = 4.9 -9.8×5.045 = 4.9 - 49.44 = -44.54 m/s
The final velocity is -44.54 m/s, and it took 5.045s to reach the ground.
To see if your results are reasonable, you can compare the final velocity of the stone as it falls down unwinding the wire from the pulley, to the velocity the stone would have if falling the same distance while unconnected to the pulley. What is the velocity of an untethered stone after falling 0.337 m from rest
Answer:
The velocity of the stone is 2.57 m/s.
Explanation:
Given that
Height = 0.337 m
We need to calculate the velocity of the stone
Using equation of motion
[tex]v^2-u^2=2gh[/tex]
Where, v = velocity of stone
u = initial velocity
g = acceleration due to gravity
h = height
Put the value into the formula
[tex]v^2-0=2\times9.8\times 0.337[/tex]
[tex]v=\sqrt{2\times9.8\times0.337}[/tex]
[tex]v=2.57\ m/s[/tex]
Hence, The velocity of the stone is 2.57 m/s.
A ball with a mass of 0.5 kg is attached to one end of a light rod that is 0.5 m long. The other end of the rod is loosely pinned at a frictionless pivot. The rod is raised until it is vertical, with the ball above the pivot. The rod is released and the ball moves in a vertical circle. The tension in the rod as the ball moves through the bottom of the circle is closest to:
Answer:
The tension in the rod as the ball moves through the bottom circle is 9.8 N
Explanation:
When the ball is released from rest, the centripetal force equals the weight of the ball. So mv²/r = mg where m = mass of ball = 0.5 kg, v = speed of ball, r = radius of vertical circle = length of rod = 0.5 m and g = acceleration due to gravity = 9.8 m/s²
v = √gr = √9.8 m/s² × 0.5 m = √4.9 = 2.21 m/s
Now at the bottom of the circle T - mg = mv²/r where T = tension in the rod
T = m(g + v²/r)
= m(g + (√gr)²/r)
= m(g+ gr/r)
= m(g + g)
= 2mg
= 2 × 0.5 kg × 9.8 m/s²
= 9.8 N
So, the tension in the rod as the ball moves through the bottom circle is 9.8 N
Pesure is defined
the force
over a
given
area.
Answer:yes absolutely
Explanation:
Answer:
pressure is a force acting on a unit area and its SI unit is pascals (Pa)
to find pressure: Force/Area
Explanation:
Which two possible explanations does the video give for why white light changes into colored light? Color is an impurity added to white light by the prism. Color is present in the materials on which white light shines. White light contains seven colors, which are separated by the prism. White light reacts with chemicals in the air to produce seven colors.
Answer:
White light contains seven colors, which are separated by the prism.
White light reacts with chemicals in the air to produce seven colors.
Explanation:
It was first observed by Sir Issac Newton, that when white light is passed through a prism, an elongated, coloured patch of light is obtained on a screen placed behind the prism. The seven colours obtained constitute the spectrum of white light.
In nature, white light is separated into its constituent wavelengths when white light interacts with substances in the atmosphere.
Answer:
The correct answer is “color is an impurity added to white light by the prism.”
and
“White light contains seven colors, which are separated by the prism
Explanation:
State 1 difference between 1 way rotary motion and reversible rotary motion
Answer:
The difference between One-way as well as reversible rotary motion is described below.
Explanation:
Unless rotary motions occur restricted to single direction exclusively (i.e. whether clockwise as well as anti-clockwise only), it is defined as another rotary 'one-way' motion.This motor establishes that continuously variable movement at 360 ° chemically guided is conceivable. The rotating is regulated, and for a particular direction, the biochemical occurrences guiding rotation become incredibly selective.How can you define a solution to an equation?
Figure 3 shows a stationary metal block hanging from the middle of a stretched wire which is suspended from a horizontal beam. The tension in each half of the wire is 15 N. (a) Calculate for the wire at A, (i) the resultant horizontal component of the tension forces, (ii) the resultant vertical component of the tension forces. Can someone explain why the first one is 0?
Explanation:
(i) The horizontal component of the tension in the right wire points right, and the horizontal component of the tension in the left wire points left. Since these components are equal and opposite, the resultant horizontal force is 0.
∑Fₓ = 15 N cos 20° − 15 N cos 20°
∑Fₓ = 0 N
(ii) ∑Fᵧ = 15 N sin 20° + 15 N sin 20°
∑Fᵧ = 10.26 N
i) The resultant horizontal component of the tension forces is 0N
ii) The resultant vertical component of the tension forces is 10.26N
iii) The sum of force along the horizontal is zero because the force has the same magnitude and moving in the opposite direction.
i) From the given figure, the horizontal component of the force is given as;
[tex]F_x = + 15 cos 20^0 + (-15cos20^0)\\F_x = + 15 cos 20^0 -15cos20^0\\F_x =0[/tex]
The sum of force along the horizontal is zero because the force has the same magnitude and moving in the opposite direction.
ii) The vertical component of the force is expressed as
[tex]F_y = + 15 sin 20^0 + 15sin20^0)\\F_y = 2(15sin20^0)\\F_y=2(5.13)\\F_y=10.26N[/tex]
Hence the resultant vertical component of the tension forces is 10.26N
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Daniel plans to have a garage sale. Research trends suggest that the best time to have a garage sale is before major U.S. holidays, when people are looking for discounted purchases. Based on scientific knowledge and trends, which of these would be the most favorable month for Daniel to have a garage sale?
Complete question is;
Daniel plans to have a garage sale. Research trends suggest that the best time to have a garage sale is before major U.S. holidays, when people are looking for discounted purchases. Based on scientific knowledge and trends, which of these would be the most favorable month for Daniel to have a garage sale? April January July November
Answer:
November
Explanation:
We are told the best time to have a garage sale is before major US holidays.
Now, from the options given, the months that have the highest major US holidays are January and November.
January has New years day and Martin Luther King Jr's day. While November has veterans day and Thanksgiving day.
Now, the 2 months immediately after January has no major US holiday whereas, the 2 months after November have 2 major US holidays each.
Thus, the best option is November
Which best describes what happens if two waves meet and build on each other? constructive interference destructive interference reflection absorption
Answer:
Which best describes what happens if two waves meet and build on each other?
constructive interferencedestructive interference
reflection
absorption
Explanation:
When two waves meet in phase they will overlap together and form a constructive interference. The resultant amplitude of the waves will be greater than that of individual waves.
What is interference ?A wave of greater, lower, or the same amplitude is created when two waves merge through interference by combining their displacements at all points in space and time.
The interaction of waves that are coherent or correlated with one another, either because they originate from the same source or because their frequencies are similar or almost identical, leads to both constructive and destructive interference.
All sorts of waves, including light, radio, acoustic, surface water waves, gravity waves, and matter waves, can exhibit interference effects. In constructive interference, the waves are in single phase forms a resultant wave with higher amplitude.
When waves from out of phase meets, the resultant wave will have an amplitude less than the individual amplitudes. Here, the waves are meet in phase and build on each is constructive interference.
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A stone is dropped from the same height at Terai and at the top of the
mountain. Where does it fall faster? Why?
Answer:
It will fall at the same speed in both locations
Explanation:
When an object is falling, it is accelerated to the same degree irrespective of the height from which it is falling.
All objects on the earth's surface experience an acceleration due to gravity. This acceleration due to gravity is the same for all objects irrespective of their height or mass.
Hence for a stone dropped from the same height as Terai and the top of a mountain, the acceleration due to gravity is the same in both cases hence they will fall at the same speed.
HELPPP!! ASAPPP!! PLEASEEE
Answer: 9.675 Hz .
Explanation:
Given, velocity of waves = 12.9 m/s
Length of string = 2.00 m
Let [tex]\lambda[/tex] be the wavelength , then for 3 loops
[tex]\dfrac{3}{2}\lambda= \text{length of string}\\\\\Rightarrow\ \dfrac{3}{2}\lambda= 2\ m\\\\\Rightarrow\ \lambda= \dfrac{4}{3}\ m[/tex]
Now , velocity = frequency x wavelength
Then, frequency = [tex]\dfrac{velocity}{wavelength}[/tex]
[tex]=\dfrac{12.9\times3}{4}\\\\=9.675\ Hz[/tex]
hence, it will create standing waves with 3 loops at 9.675 Hz .
why do objects located further away from pivot have a greater moment?
Answer:
because us equal to the anticlockwise moment about that pivot.If the object are balanced:clockwise.
Explanation:
This is when an object placed on something narrow object that can act as a pivot too fir example a plank placed on a brick.Finally the edges or the curve
Answer:
Moment about a point= force × perpendicular distance
When an object is further from the pivot, the perpendicular distance of the object from the pivot increases. Since moment is the product of the force and the perpendicular distance, when the perpendicular distance increase, the moment increases too. Thus, objects located further away from the pivot have a greater moment.
is the body temperature of every person 37 degree Celsius. Why?
Answer:
Scientists have found the reason why our body temperature is 98.6°farehenheit (37°c). Apparently it's the perfect balance as it's warm enough to prevent fungal infection but not so hot that we need to eat nonstop to maintain our metabolism. ... So we know we need a higher body temperature to ward off fungal infection.
What is a substance?
A. a uniform mixture that can't be separated
В.a mixture that can be separated
С. a single component that can't be separated
D. a single component that can be separated
Answer:
С. a single component that can't be separated
Explanation:
Substance : It is the pure form of matter or we can say that it is a matter that contains only one type of molecule of atom. It can not be separated by physical process.
For example : Water is a substance.
Mixture : It is a combination of different type of atoms or molecules and it is an impure form.
For example : Sodium chloride with water is a mixture.
Hence, the correct option is, (C) a single component that can’t be separated.
A substance is a single component that can't be separated by the physical process therefore the correct answer is option C.
What is a Chemical compound?
A chemical compound is a mixture of two or more chemical components, whether they are related or unrelated.
For instance, the molecular H2O is composed of one hydrogen atom and two oxygen atoms.
For instance, water is a material that cannot be physically divided yet may be separated using electrolysis.
Mixture: This impure form is made up of several different kinds of atoms or molecules.
A mixture is, for instance, sodium chloride and water.
As a result, (C), a single, irreducible component, is the right answer.
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what is acceleration produced by a force of 12 newton exerted on an object of mass 3kg
Answer:
a=F/m
a=12N/3kg (here newton can be written as kgm/s^2 so kg will be cancelled)
a=4m/s^2
Explanation:
Which has more mass, a 10 N object on the moon, or a 10 N object on the Earth?
Answer:
10N object on the earth
Gravity on moon is one sixth of earth
So a mass weighing 10N weighs 60N on earth .
So a 10N object on moon has more mass
Which statement correctly describes the quantitative relationship between acceleration and net force on an object shown in the data table? (1 point) When the net force applied to an object changes, the mass of the object remains constant. When the net force applied to an object changes, the acceleration changes by a different factor. When the net force applied to an object changes, the mass of the object also changes. When the net force applied to an object changes, the acceleration changes by the same factor.
Answer:
The correct answer is A
Explanation:
Because when the net force applied to an object changes, the acceleration changes by the same factor. This answer is correct and I hope it helps you too.Hope this helps....
Have a nice day!!!!
The statement that correctly describes the quantitative relationship between acceleration and the net force on an object shown in the data table is as follows:
When the net force applied to an object changes, the acceleration changes by the same factor.Thus, the correct option for this question is D.
What is Acceleration?Acceleration may be defined as a type of rate at which the velocity of an object may change with respect to time. This change in velocity may come in terms of both speed and direction. Acceleration is a type of vector quantity because it has both magnitude and direction.
According to the context of this question, when the net force applied to an object may change, the acceleration may also change. This change is significantly induced by the same factor. This is because the acceleration of an object may directly rely on the net force applied.
Therefore, when the net force applied to an object changes, the acceleration changes by the same factor. Thus, the correct option for this question is D.
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