Answer:
F = 64800 N
Explanation:
Given that,
Initial speed of a car, u = 70 km/h = 19.44 m/s
Finally it comes to a stop, v = 0
Time,t = 450 ms
The mass of the car is 1500 kg
We need to find the force exerted on the car. The force exerted on an object is given by :
F = ma
So,
[tex]F=\dfrac{m(v-u)}{t}\\\\F=\dfrac{1500\times (19.44-0)}{450\times 10^{-3}}\\\\F=64800\ N[/tex]
So, the required force is equal to 64800 N.
Calculate the speed of an object that travels 75m in 15s.
Approximate the human form as an unclothed vertical cylinder of 0.3 m diameter and 1.75 m length with a surface temperature of 30 oC.(a)Calculate the heat loss in a 10 m/s wind at 20 oC.(b)What is the heat loss if the skin is covered with a thin layer of water (i.e., sweat) at 30 oC and the relative humidity of the air is 60 %
Answer:
[tex]q=1118.865W[/tex]
Explanation:
From the question we are told that
Diameter of the cylinder [tex]D=0.3m[/tex]
Length of the cylinder [tex]L=1.75m[/tex]
Surface temperature of cylinder [tex]T_s=30 \textdegree C=303k[/tex]
Speed of air [tex]V=10m/s[/tex]
Temperature of air [tex]T=20 \textdegree C[/tex]
Generally the equation for Reynolds number is mathematically given by
[tex]Re_D=\frac{VD}{v}[/tex]
where
[tex]v=15.27*10^-^6[/tex]
[tex]Re_D=\frac{10*0.3}{15.27*10^-^6}[/tex]
[tex]Re_D=1.96*10^5[/tex]
Generally the equation for Nusselt number is mathematically given by
[tex]N_u=0.6(Re_D)^{0.6}(Pr)^{0.37}[/tex]
where
Prandtl number
[tex]Pr=0.71[/tex]
[tex]N_u=0.6(Re_D)^{0.6}(Pr)^{0.37}[/tex]
[tex]N_u=0.6(1.96*10^5)^{0.6}(0.71)^{0.37}[/tex]
[tex]N_u=791.53[/tex]
Generally the equation for convective heat transfer is mathematically given by
[tex]h=Nu \frac{k}{D}[/tex]
where
[tex]k=25.7*10^{-3}[/tex]
[tex]h=791.53*\frac{25.7*10^{-3}}{0.3}[/tex]
[tex]h=67.81W/m^2K[/tex]
Generally the equation for surface area of a cylinder is mathematically given by
[tex]A=\pi DL[/tex]
[tex]A=\pi *0.3*1.75[/tex]
[tex]A=1.65m^2[/tex]
Generally the equation for convective heat transfer is mathematically given by
[tex]q=h4(T_s-T_{inty)}[/tex]
[tex]q=(67.81)*1.65*(30-20)\\[/tex]
[tex]q=1118.865W[/tex]
Calculate the net force for each of the following:
a.
20 N to the right and 30 N to the right:
Answer and Explanation:
A.
There would be a net force of 50 N going to the right.
Since both forces are going right, they add onto the force amount.
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please help asap
Ms. Brando’s students are studying forces. She has assigned a fun task: designing a balloon car. The students must design a car and see which model will travel the greatest distance. The basic design of the cars can be seen here. First the balloon is inflated and attached to the car. It is important to keep the balloon closed. Once attached to the car, the stem of the balloon is opened and air rushes out through the straw. The air goes one way; the car moves in the other direction. There are no restrictions on the design other than the students must use the materials given to them by Ms. Brando. What is the source of the force that moves the car? A) The circumference of the balloons. B) The friction between the wheels and the track surface. C) The air rushing out of the balloon through the straw. D) The mass of the car: the lighter the car the farther it moves.
Answer: a
Explanation:
when a car dives on a road it a makes friction but it need something to push it or start it which is the balloon in this example
(sorry if im wrong)
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Which of these is one of the five determinants of health?
A. The gender of your doctor
B. Your access to health services
C. The type of sport you play
D. The amount
your insurance deductible
Answer:
B
Explanation:
HELP PLEASE
Two 24 ohm resistors are in parallel and placed across a 12 V battery. What is the current in each branch of the circuit?
20 A
0.0125 A
0.5 A
.
Answer:
.5 A
Explanation:
As an admirer of Thomas Young, you perform a double-slit experiment in his honor. You set your slits 1.01 mm apart and position your screen 3.09 m from the slits. Although Young had to struggle to achieve a monochromatic light beam of sufficient intensity, you simply turn on a laser with a wavelength of 639 nm . How far on the screen are the first bright fringe and the second dark fringe from the central bright fringe
Answer:
[tex]0.00195\ \text{m}[/tex]
[tex]0.00293\ \text{m}[/tex]
Explanation:
m = Order = 1
D = Distance between screen and slit = 3.09 m
d = Slit distance = 1.01 mm
[tex]\lambda[/tex] = Wavelength = 639 nm
Distance from the first bright fringe from the central bright fringe is given by
[tex]y=\dfrac{m\lambda D}{d}\\\Rightarrow y=\dfrac{1\times 639\times 10^{-9}\times 3.09}{1.01\times 10^{-3}}\\\Rightarrow y=0.00195\ \text{m}[/tex]
Distance from the first bright fringe from the central bright fringe is [tex]0.00195\ \text{m}[/tex]
Distance from the second dark fringe from the central bright fringe is given by
[tex]y=(m+\dfrac{1}{2})\dfrac{\lambda D}{d}\\\Rightarrow y=(1+\dfrac{1}{2})\dfrac{639\times 10^{-9}\times 3.09}{1.01\times 10^{-3}}\\\Rightarrow y=0.00293\ \text{m}[/tex]
Distance from the second dark fringe from the central bright fringe is [tex]0.00293\ \text{m}[/tex].
A woman has one damaged fallopian tube. The damage completely blocks the opening of the tube at the ovary. How will this most likely affect her fertility?
Her likelihood of conceiving will be reduced by at least 50%.
Her eggs, if fertilized, will not implant properly.
Her eggs will not mature inside the ovary.
Her chances of conceiving twins will be doubled.
Answer:Her likelihood of conceiving will be reduced by at least 50%.
Explanation:
EDGE 2020
Answer:
Her likelihood of conceiving will be reduced by at least 50%
Explanation:
took the test on edge, got it right
You are pulling with 57 N on a heavy bookshelf, but the bookshelf doesn't move. What is the force of static friction in Newtons acting on the bookshelf?
Answer:
57N
Explanation:
Since the bookshelf isn't moving, the force you're exerting on the shelf must be equal to the force of static friction
So the force of static friction is 57N
A coaxial cable consists of an inner cylindrical conductor of radius 3 cm on the axis ofan outer hollow cylindrical conductor of inner radius 7 cm and outer radius of 10 cm.The inner conductor carries current 4.5 A in one direction, and the outer conductor carries current 8 A in the opposite direction. What is the value of the magnetic field atfollowing distances from the axis of the cable:
Answer:
Hello your question lacks some information and that is the distance
At r = 0.150 m (outside the cable) note : (μ 0 = 4π × 10-7 T · m/A)
answer: 4.7 * 10^-6 T
Explanation:
R1 = 0.03 m
R2 = 0.07 m
R3 = 0.1 m
Inner conductor carries current = 4.5A in one direction
outer conductor carries current = 8A in opposite direction
Determine the value of magnetic field at r = 0.150 m
net current = 8 - 4.5 = 3.5 A
∴ β ( value of magnetic field )
= ( 4π * 10^-7 * 3.5 ) / ( 2π * 0.150 )
= 4.4*10^-6 / 0.94
= 4.7 * 10^-6 T
Why is no image formed when an object is at the focal point of a converging lens?
Answer:
the refracted rays neither converge nor diverge. After refracting, the light rays are traveling parallel to each other and cannot produce an image.
Explanation:
How does Newton’s first second and third laws apply to eating your breakfast
Answer:
Newton's third law states that for every action (force) in nature there is an equal and opposite reaction. In other words, if object A exerts a force on object B, then object B also exerts an equal and opposite force on object A. Notice that the forces are exerted on different objects. However much you push your fork in the food, that much a dent it will cause.
Explanation:
Answer:
¡I hope it helps you! :) .................
Which direction do longitudinal waves travel?
Answer:
If the particles of the medium vibrate in a direction parallel to the direction of propagation of the wave, it is called a longitudinal wave. In longitudinal waves, the particle movement is parallel to the direction of wave propagation.
Explanation:
You and a friend are playing with a bowling ball to demonstrate some ideas of Rotational Physics. First, though, you want to calculate the Rotational Kinetic Energy of the bowling ball as it rolls down a sidewalk without slipping. This means it has both linear kinetic energy and rotational kinetic energy. A bowling ball can be modeled as a solid sphere rotating about its center. This bowling ball has a mass of 6.40 kg and a radius of 0.130 m. You'll need to look up the equation for the Moment of Inertia in your textbook. It is rotating with an angular velocity of 16.0 radians / second in the counter-clockwise (or positive) direction. You can use this to determine the linear velocity of the bowling ball (since it is rolling without slipping). What is the Total Kinetic Energy of the bowling ball
Answer:
K_{total} = 19.4 J
Explanation:
The total kinetic energy that is formed by the linear part and the rotational part is requested
[tex]K_{total} = K_{traslation} + K_{rotation}[/tex]
let's look for each energy
linear
[tex]K_{traslation}[/tex] = ½ m v²
rotation
[tex]K_{rotation}[/tex] = ½ I w²
the moment of inertia of a solid sphere is
I = 2/5 m r²
we substitute
[tex]K_{total}[/tex] = ½ mv² + ½ I w²
angular and linear velocity are related
v = w r
we substitute
K_{total} = ½ m w² r² + ½ (2/5 m r²) w²
K_{total} = m w² r² (½ + 1/5)
K_{total} = [tex]\frac{7}{10}[/tex] m w² r²
let's calculate
K_{total} = [tex]\frac{7}{10}[/tex] 6.40 16.0² 0.130²
K_{total} = 19.4 J
explain why when water is poured on a dry class slab it spreads uniformly but it forms spherical droplets on a waxed glass slab
Answer and Explanation:
The texture of the slabs affects the type of bonding the water molecules has with each other.
The dry glass slab allows the water to form cohesive bonds with each other, making the water stick to itself and not the slab, which makes it flow uniformly, or regularly.
The Waxed glass slab has a different texture that forms an adhesive-type bonding with water, making the water stick to the slab at certain parts/forming the spherical droplets.
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why does ice melt faster in water than in oil when both liquids are at the same temperature
Answer:
Because water has a high specific heat, each little bit of water flowing past can give lots of thermal energy to the ice cube. Oil has a smaller specific heat, and so more oil has to flow past to give the same amount of heat energy to the ice cube. ... Colder oil will melt ice less rapidly than warmer oil or water
An object has a mass of 50 kg on Earth. What would be the mass of that object in the Moon
It would be 50 kg.
Mass doesn't change.
Weight can.
Please PLEASE HELP ASAP
A student placed four objects on a plastic tray: a rock, an eraser, a wood block, and an ice cube. The student slowly lifts the tray and measures the height at which each object begins to slide in order to compare the friction of each object. The table above shows the results. In a separate experiment the student used the same objects and tray, but glued a piece of gritty sandpaper to the tray. What results would be expected? A) The items would slide faster at the same heights. B) The items would start to slide when the tray is not lifted as high. C) The items would not slide at all, no matter how high the tray is raised. D) The tray would need to be raised higher before the items start to slide.
Answer:
D) The tray would need to be raised higher before the items start to slide.
Explanation:
The tray would need to be raised higher due to the gritty sandpaper causing it to have more grip or fraction between the two surfaces. In the first experiment it would have a smooth surface to slide across but in the second experiment it would have a rougher surface to slide across.
Example: It would be like taking two different kinds of shoes like tennis shoes and football cleets. Then seeing which one has more traction when going up a hill.
Hope this helps!!
In the nitrogen cycle, plants take in nitrates and convert them into
Read each example and identify whether the data are observations or inferences from observations. The fish’s ventral fin measured 8.5 cm long.
Answer:
Observation
Inference
Inference
Observation
Inference
Explanation:
Question 6.Why does a ball dropped from a certain height not bounce back 1 point
to the same height it was dropped from? *
Answer:
Because the coefficient of restitution is less than 1.
This coefficient is 1 for a perfectly elastic collision.
Some of the energy of the fall is absorbed by the ball so the ball cannot return to its original height.
Also, you have the effects of air resistance and some energy absorption of the the reflecting surface.
Will give brainliest!!
How much KClO3 is needed to make a saturated solution in 100 mL of water at 70⁰ C?
Answer:
iam not sure but I think its NaNO3
Which of these is an example of tertiary prevention?
A. Getting screened for skin cancer
B. Avoiding smoking and drinking alcohol
C. Dialysis for damaged kidneys
D. Washing hands
Explanation:
because a tertiary prevention is when the person is already infected with the disease
Speed and time play a major factor in:
Scrimmage
Tactical movement
Situation awareness
Drill
Answer:
Tactical movement
Explanation:
Speed and time play a significant factor in Tactical movement. The correct option is B.
What is a Tactical movement?Tactical movement refers to the coordinated and strategic movement of military units or teams to achieve a specific objective. It is a fundamental aspect of military operations and involves the use of various tactics and techniques to move troops and equipment safely and efficiently on the battlefield.
Tactical movement can involve various modes of transportation, such as on foot, in vehicles, or by air. It also involves the use of cover and concealment to avoid detection by the enemy, and the use of communication and signal systems to coordinate movements and maintain situational awareness.
The success of the tactical movement depends on many factors, including the terrain and weather conditions, the size and composition of the units involved, the available resources and equipment, and the tactics and strategies employed by both friendly and enemy forces. It requires careful planning, training, and execution to ensure that the movement is successful and achieves the desired outcome.So, tactical movement is an essential component of military operations, and plays a critical role in achieving victory on the battlefield.
Here in the Question,
Tactical movement refers to the movement of military units or teams in a coordinated and strategic manner to achieve a specific objective. In such movements, speed and time are critical factors because they determine the success or failure of the mission. The speed of movement can help to surprise the enemy, take advantage of a weakness in their defense, or seize a key position before they can respond. Time is also important because the longer it takes to achieve the objective, the more likely the enemy is to detect and counter the movement. Therefore, tactical movement requires careful planning and execution to ensure that the right units move at the right speed and at the right time to achieve the desired outcome.
Therefore, the correct option is B i.e Tactical movement.
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Which statement best explains the difference between longitudinal and transverse waves?
A: Longitudinal waves have troughs, while transverse waves have crests.
B: Longitudinal waves transfer energy while transverse waves do not
C: Longitudinal waves produce energy, while transverse waves consume energy
D: Particles in longitudinal waves travel in the direction of the wave, while particles in transverse waves travel perpendicular to the wave.
pls put the letter in the answer
Answer:
the answer here would be A
The statement that best explains the difference between longitudinal and transverse waves is D: Particles in longitudinal waves travel in the direction of the wave, while particles in transverse waves travel perpendicular to the wave. The correct option is D.
What is a wave?A wave is a disturbance that propagates through space and time, transferring energy without transferring matter. Waves can be found in various forms, such as sound waves, light waves, and water waves.
A transverse wave is a type of wave where the particles of the medium vibrate perpendicular to the direction of wave propagation.
In other words, the motion of the particles is at right angles to the direction of the energy transfer. A common example of transverse waves is light waves.
A longitudinal wave is a type of wave where the particles of the medium vibrate parallel to the direction of wave propagation. The motion of the particles is in the same direction as the energy transfer. An example of longitudinal waves is sound waves.
In a longitudinal wave, particles in the medium oscillate back and forth along the direction of the wave, creating areas of compression and rarefaction. In a transverse wave, particles in the medium oscillate up and down, creating crests and troughs.
Therefore, the correct statement is Particles in longitudinal waves travel in the direction of the wave, while particles in transverse waves travel perpendicular to the wave(D).
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41. 2072 Set E Q.No. 11 A source of sound produces a note of
512 Hz in air at 17°C with wavelength 66.5 cm. Find the ratio
of molar heat capacities at constant pressure to constant
volume at NTP. Densities of air and mercury at NTP are
1.293 kg/m3 and 13600 kg/m3 respectively.
Ans: 1.36
Why are objects that fall near Earth's surface rarely in free fall?
O Gravity does not act on objects near Earth's surface.
O Air exerts forces on falling objects near Earth's surface.
O The objects do not reach terminal velocity.
O The objects can be pushed upward by gravity.
Answer:
Air exerts forces on falling objects near earth's surface
Explanation:
Falling objects are typically subject to air resistance which prevents the force of gravity on the object
Lithium was one of the metals studied by the American physicist Robert Millikan in his research on the photoelectric effect. When illuminated with blue light of frequency 6.64 x 10" Hz, the photoelectrons ejected from a lithium surface have a maximum kinetic energy of 0.332 eV. What is the threshold frequency for lithium? For this problem, let the value of Planck's constant, h, be 6.63 x 10J's
Answer:
f = 7.9487 10¹³ Hz
Explanation:
The photoelectric effect was correctly explained by Einstein assuming that the radiation is composed of photons, which behave like particles.
hf = K + Ф
It indicates the frequency and the kinetic energy, let's look for the work function
Ф = hf - K
let's reduce the magnitudes to the SI system
K = 0.332 eV (1.6 10⁻¹⁹ J / 1 eV) = 0.5312 10⁻⁻¹⁹ J
let's calculate
Ф = 6.63 10⁻⁻³⁴ 6.64 10¹¹ - 0.5312 10⁻¹⁹
Ф = 4.40 10⁻²² - 0.5312 10⁻¹⁹
Ф = 5.27 10⁻²⁰ J
for the minimum frequency that produces photoelectrons, the kinetic energy is zero
hf = Ф
f = Ф / h
f = 5.27 10⁻²⁰ / 6.63 10⁻³⁴
f = 7.9487 10¹³ Hz
describe the human condition before Science and technology was practice.
An example of conservation of angular momentum is jumping on a Merry-Go-Round. Watch this video (it starts part way through but the only thing you miss is the people pushing the Merry-Go-Round) to see someone jumping on a Merry-Gr-Round in motion like this problem. You can model the Merry-Go-Round as a solid disk with a radius of 2.70 m and a mass of 77.0 kg. Initially the Merry-Go-Round has an angular velocity 7.40 radians / second. Then the person jumps on and change the Moment of Inertia of the system. The person lands on the outer edge of the Merry-Go-Round and has a mass of 58.0 kg. What is the final angular velocity of the system after the person jumps on
Answer:
ωf = 2.95 rad/sec
Explanation:
Assuming no external torques acting while the person jumps on, total angular momentum must be conserved.Angular momentum for a rotating rigid body can be expressed as follows:[tex]L = I * \omega (1)[/tex]
where I = moment of inertia regarding the rotating axis, and ω= angular velocity.Since total angular momentum must be conserved, this means that the following equality must be satisfied:[tex]L_{o} = L_{f} (2)[/tex]
The initial angular momentum, taking into account that the Merry-Go-Round can be modeled as solid disk, can be expressed as follows:[tex]L_{o} = I_{o} * \omega_{o} = \frac{1}{2}* M* R^{2}* \omega_{o} =\\ \frac{1}{2} * 77.0 kg* (2.70m)^{2}* 7.40 rad/sec = 2076.92 kg*m2*rad/sec (3)[/tex]
The final angular momentum, is just the product of the new moment of inertia times the final angular velocity.The new moment of inertia, is just the sum of the original moment of inertia I₀ and the moment of inertia due to the person that jumps on.Assuming that we can treat him as a point mass, his moment of inertia is just the product of his mass times to the distance to the axis of rotation (the radius of the Merry-Go-Round) squared.So, we can write the new moment of inertia If as follows:[tex]I_{f} = I_{o} +( m_{p} * R^{2}) = (\frac{1}{2} * M* R^{2}) + ( m_{p} * R^{2}) =\\ (\frac{1}{2} * 77.0 kg* (2.70m)^{2}) +( 58.0 kg * (2.70m)^{2}) = \\ 280.67 kg*m2 + 422.82 kg*m2 = \\ 703.49 kg*m2 (4)[/tex]
The final angular momentum can be written as follows:[tex]L_{f} = I_{f} * \omega_{f} (5)[/tex]
Since (3) and (5) must be equal each other, replacing If by its value from (4) in (5), we can solve for ωf, as follows:[tex]\omega_{f} = \frac{L_{o} }{I_{f}} = \frac{2076.92kg*m2*rad/sec}{703.49kg*m2} = 2.95 rad/sec (6)[/tex]
