Answer:
D.
correct me if im wrong
brainlest plsss<333
A box of mass 7.7 - kg is accelerated from rest across a floor at a rate of 2.6 m/s2 for 18.5 s. Find the net work done on the box
Answer:
Explanation:
The net work will change the kinetic energy
W = ½mv² = ½m(at)² = ½ma²t²
W = ½(7.7)2.6²(18.5²) = 8907.3985 = 89 kJ
If a force of 20kn acts on a circular rod of a diameter 10mm, calculate the stress of the rod
σ = F/A = F/ (πD²/4) = 20000 / (π0.10²/4) = 2.55 MN/m²
As a result of friction, the angular speed of a wheel changes with time according to dθ/dt = ω0e^−σt where ω0 and σ are constants. The angular speed changes from 3.70 rad/s at t = 0 to 2.00 rad/s at t = 8.60 s.
a. Use this information to determine σ and ω0.
σ = _______s−1
ωo = ______rad/s
b. Determine the magnitude of the angular acceleration at t = 3.00 s.
______rad/s2
c. Determine the number of revolutions the wheel makes in the first 2.50 s
_______rev
d. Determine the number of revolutions it makes before coming to rest.
_______rev
Hi there!
a.
We can use the initial conditions to solve for w₀.
It is given that:
[tex]\frac{d\theta}{dt} = w_0e^{-\sigma t}[/tex]
We are given that at t = 0, ω = 3.7 rad/sec. We can plug this into the equation:
[tex]\omega(0)= \omega_0e^{-\sigma (0)}\\\\3.7 = \omega_0 (1)\\\\\omega_0 = \boxed{3.7 rad/sec}[/tex]
Now, we can solve for sigma using the other given condition:
[tex]2 = 3.7e^{-\sigma (8.6)}\\\\.541 = e^{-\sigma (8.6)}\\\\ln(.541) = -\sigma (8.6)\\\\\sigma = \frac{ln(.541)}{-8.6} = \boxed{0.0714s^{-1}}[/tex]
b.
The angular acceleration is the DERIVATIVE of the angular velocity function, so:
[tex]\alpha(t) = \frac{d\omega}{dt} = -\sigma\omega_0e^{-\sigma t}\\\\\alpha(t) = -(0.0714)(3.7)e^{-(0.0714) (3)}\\\\\alpha(t) = \boxed{-0.213 rad\sec^2}[/tex]
c.
The angular displacement is the INTEGRAL of the angular velocity function.
[tex]\theta (t) = \int\limits^{t_2}_{t_1} {\omega(t)} \, dt\\\\\theta(t) = \int\limits^{2.5}_{0} {\omega_0e^{-\sigma t}dt\\\\[/tex]
[tex]\theta(t) = -\frac{\omega_0}{\sigma}e^{-\sigma t}\left \| {{t_2=2.5} \atop {t_1=0}} \right.[/tex]
[tex]\theta = -\frac{3.7}{0.0714}e^{-0.0714 t}\left \| {{t_2=2.5} \atop {t_1=0}} \right. \\\\\theta= -\frac{3.7}{0.0714}e^{-0.0714 (2.5)} + \frac{3.7}{0.0714}e^{-0.0714 (0)}[/tex]
[tex]\theta = 8.471 rad[/tex]
Convert this to rev:
[tex]8.471 rad * \frac{1 rev}{2\pi rad} = \boxed{1.348 rev}[/tex]
d.
We can begin by solving for the time necessary for the angular speed to reach 0 rad/sec.
[tex]0 = 3.7e^{-0.0714t}\\\\t = \infty[/tex]
Evaluate the improper integral:
[tex]\theta = \int\limits^{\infty}_{0} {\omega_0e^{-\sigma t}dt\\\\[/tex]
[tex]\lim_{a \to \infty} \theta = -\frac{\omega_0}{\sigma}e^{-\sigma t}\left \| {{t_2=a} \atop {t_1=0}} \right.[/tex]
[tex]\lim_{a \to \infty} \theta = -\frac{3.7}{0.0714}e^{-0.0714a} + \frac{3.7}{0.0714}e^{-0.0714(0)}\\\\ \lim_{a \to \infty} \theta = \frac{3.7}{0.0714}(1) = 51.82 rad[/tex]
Convert to rev:
[tex]51.82 rad * \frac{1rev}{2\pi rad} = \boxed{8.25 rev}[/tex]
Blaine and her sister are identical twins riding roller coasters at Kinetic Kars. They each ride the
roller coaster on their own once. Next time, they ride the roller coaster together. On which ride
do you think they have the most kinetic energy? Explain your answer using information from class
activities.
A jet is flying at a speed of 700 kilometers per hour. The pilot encounters turbulence due to a 50-kilometer- per-hour wind blowing at an angle of 47°. Find the resultant force on the plane.
Answer:
F = 0 N
Explanation:
The problem does not talk about any acceleration. We can just assume it always moves at a constant speed so the resultant force will be 0 newtons. Of course you could say that it accelerates for a certain amount of time, as the wind blows, but the problem doesn't tell us when to calculate the resultant force (if during the acceleration or after) + we don't have the mass of the jet.
An airplane accelerates from rest down a runway at 9.50 m/s2 for 29.3 seconds when it
takes off. What is the distance traveled while taking off?
Answer:
Explanation:
s = ½at²
s = ½(9.50)(29.3²) = 4,077.8275
s = 4080 m
when rounded to the three significant digits of the question numerals.
20 PTS!
If an object is moving at a constant velocity, which must be true?
Its acceleration is zero.
Its acceleration in decreasing.
Its acceleration is increasing,
Its acceleration is a non-zero constant.
[tex]\huge \bf༆ Answer ༄[/tex]
The Correct choice is ~ A
[tex] \textsf{its \: acceleration \: is \: zero}[/tex]If an object moves at a constant velocity, then the change in velocity over the time is 0, Acceleration is defined as rate of change in velocity but since there is no change in velocity, the value of Acceleration is equal to Zero.
An LED is useful because when a current passes through it, it gives out... what?
Enter your answer
An LED is useful because when a current passes through it, it gives out light.
An LED is useful because when a current passes through it, it gives out Light.
What is an LED?
LED, in full light-emitting diode, in electronics, a semiconductor device that emits infrared or visible light when charged with an electric current.
A light-emitting diode (LED) emits light by applying a forward current to the pn junction of a compound semiconductor.
When forward current is passed through the light-emitting diode, carriers (electrons and holes) move. The holes in the p-type region move to the n-type region and the electrons in the n-type region move to the p-type region. The injected carriers recombine, and the energy difference before and after recombination is released as light. The emitted light depends on the energy band gap (Eg) of the compound semiconductor.
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identify the origins of breakdown when using a spectrum analyzer
Four regions of the electromagnetic spectrum that astronomers use when observing objects in the space are the following enumerated answers.
1. First is Ultraviolet
2. Next is Infrared
3. Then the radio
4. Lastly the Visible lights.
These are the answers to the problem.
A baseball is hit with a speed of 27.0 m/s at an angle of 47.0 ∘ . It lands on the flat roof of a 10.0 m -tall nearby building. Part A If the ball was hit when it was 1.3 m above the ground, what horizontal distance does it travel before it lands on the building?
Answer:
H = Vy t - 1,2 g t^2 formula for height of ball after t sec
H = 10 - 1.3 = 8.7 m
Vy = 27 sin 47 = 19.7 m/s vertical speed of ball
8.7 = 19.7 t - 9.8/2 t^2 height of ball after t sec
4.9 t^2 - 19.7 + 8.7 = 0 rearranging
[19.7 ± (388 - 170)^1/2] / 2 *4.9 = [19.7 ± 14.7] / 9.8 = .51 ,3.5 sec
.51 sec would be on the way up and 3.5 sec on the way down
Sx = 27 * cos 47 * 3.5 = 64.4 m around 200 ft seems reasonable
The average value of the load between A and B is 6.0 N. The spring has an unstretched length
increases from 4.0 cm to 6.0 cm.
The change in the length of the spring as it stretches from 4.0 cm to 6.0 cm is 2.0 cm.
The change in length of the spring can be calculated by subtracting the initial unstretched length (4.0 cm) from the final stretched length (6.0 cm).
Change in length = Final length - Initial length
Change in length = 6.0 cm - 4.0 cm
Change in length = 2.0 cm
Therefore, the change in the length of the spring as it stretches from 4.0 cm to 6.0 cm is 2.0 cm. This means the spring elongates by 2.0 cm under the applied load between points A and B.
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The complete question is:
The average value of the load between A and B is 6.0 N. The spring has an unstretched length increases from 4.0 cm to 6.0 cm. What is the change in the length of the spring as it stretches from 4.0 cm to 6.0 cm?
A. 4.0 cmB. 1.0 cmC. 2.0 cmD. 6.0 cmHow is Compression Force Measured?
don't just copy theanswer please
Compression force can be measured with a force gage or load cell.
Q1) Assertion : a vector can be resolved into maximum two components
Reason : in projectile motion the velocity is resolved into vertical and horizontal components
a) Both A and R are correct; R is the correct explanation of A
b) Both A and R are correct; R is not correct explanation of A
c) A is correct; R is not correct
d) A is not correct; R is correct
Q2) Assertion : speed is constant in uniform circular motion
Reason : acceleration is constant in uniform circular motion
a) Both A and R are correct; R is the correct explanation of A
b) Both A and R are correct; R is not correct explanation of A
c) A is correct; R is not correct
d) A is not correct; R is correct
Answer:
Explanation:
Q1) d) A is not correct; R is correct (sort of) but is not the reason for A.
A vector may be resolved into an infinite number of components.
Breaking a projectile motion into the vertical and horizontal components is the EASIEST way to solve it because acceleration can be assumed to be constant in both directions. Zero for horizontal and g(ravity) in the vertical. However it is not the ONLY way to do it. Other ways are much more complex.
Q2) a) Both A and R are correct; R is the correct explanation of A (sort of)
A is correct. Speed is constant in uniform circular motion.
R is correct if you call CENTRIPETAL acceleration constant. It is only constant in magnitude. The direction is always changing as the vector always points toward the center of rotation.
How is probability used in blood typing
Blood Type O AB
Probability 0.45 0.04
explain how gravitational erosion changes landforms
Answer:
Gravity can pull soil, mud, and rocks down cliffs and hillsides.
Explanation:
Gravity is responsible for erosion by flowing water and glaciers. But gravity also causes erosion directly. This type of erosion and deposition is called mass wasting.
Answer:
Erosion is another geological process that creates landforms. When mechanical and chemical weathering breaks up materials on the Earth's surface, erosion can move them to new locations. For example, wind, water or ice can create a valley by removing material. This can create new landforms.Explanation:
Hope this helps !!A rollercoaster accelerates from 10 m/s to 100 m/s2 for 25 seconds. What is the acceleration?
Answer:
A roller coasters accelerates from an initial velocity of of 6.0 m/s to a final velocity of 70 m/s over 4 seconds. What's the acceleration? Q. Acceleration only takes place when things speed up. Q. A drag racer accelerated from 0 m/s to 200 m/s in 5 s.
Explanation:
American Football originated from which two sports?
A) Soccer and Rugby
B) Rugby and Basketball
C) Cricket and Soccer
D) Soccer and Volleyball
Answer:
b rugby and basketball
Explanation:
basket ball was made by a white man
American Football originated from Soccer and Rugby. Hence, option (A) is correct.
What is American Football?American football, sometimes known as gridiron, is a team sport played by two teams of eleven players on a rectangular field with goalposts at each end. It is known simply as football in the United States and Canada. The defense, the team without the ball, seeks to halt the offense's movement and seize control of the ball for themselves.
The offence, the team in possession of the oval-shaped football, attempts to advance down the field by running with the ball or throwing it. The offence is awarded a new set of four downs to resume the drive if they successfully gain at least 10 yards in four downs or plays. If they fail, they forfeit the ball to the defense.
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Suppose a bulldozer is being hauled at 50 km/h to a construction site on the back of a flatbed truck. From which reference point would the bulldozer not appear to be moving?
Answer:
from someone watching the bulldozer from the cab of the truck or from elsewhere on the flatbed.
Explanation:
Need help asap
A scientist has invented a robot to work on the seabed. According to his calculation, the armour of the robot can withstand a maximum pressure of 10⁵ Pa exerted by the sea water. If the density of the sea water is 1025 kg/m3, what is the maximum depth of the seabed that this robot can work? [Given g = 9.81 m/s2 and rho water = 1000 kg/m3]
Answer:
Explanation:
Well which is it ? ρ = 1000 kg/m³ or ρ = 1025 kg/m³?
Obviously the sea is salt water so we can ignore ρ = 1000 kg/m³
1025 kg/m³(d m)(9.81 N/kg) = 1 x 10⁵ N/m² = Pa
d = 9.9450535...
d = 10 meters
That's if we only account for the pressure due to the water. On top of that pressure would be atmospheric pressure which is about 101000 Pa
so the robot would be a hair above its pressure limit before it even got in the water.
Cats are groomed often by their owners to remove hair. What logical inference can be made based on this statement?
Answer:
its keeps the fur straight.....im kinda confused with the question
Explanation:
the book has a mass of 2.5 kg. What net force must act on the book to mak it accelerate to the left at a rate of 7.0m/s2?
Answer:
17.5 N
Explanation:
Given :Mass (m) = 2.5 kgAcceleration (a) = 7.0 m/s²To calculate :Force exerted (F)Calculation :• F = ma→ F = (2.5 × 7.0) N
→ F = 25/10 × 7 N
→ F = 5/2 × 7 N
→ F = (5 × 7)/2 N
→ F = 35/2 N
→ F = 17.5 N towards left
Hence, 17.5 N of net force must act on the book to make it accelerate to the left.
Would you die if you take the car keys out of the ignition and throw them in the back seat while you coast down a mountain-side in an attempt to save fuel and look cool for the girl in said back seat.
Answer:
bro what.
Explanation:
... is this an actual physics question?
A 3.1 kg ball is dropped from the top of a 38 m tall building. What is the speed of the ball when it is halfway from the building to the ground? Round your answer to 2 decimal places.
Answer:
19.3m/s
Explanation:
Use third equation of motion
[tex]v^2-u^2=2gh[/tex]
where v is the velocity at halfway, u is the initial velocity, g is gravity (9.81m/s^2) and h is the height at which you'd want to find the velocity
insert values to get answer
[tex]v^2-0^2=2(9.81m/s^2)(38/2)\\v^2=9.81m/s^2 *38\\v^2=372.78\\v=\sqrt[]{372.78} \\v=19.3m/s[/tex]
Which type of muscle cell can have multiple nuclei
Answer:
Skeletal Muscle cells
Skeletal muscle cells are long, cylindrical, and striated. They are multi-nucleated meaning that they have more than one nucleus. This is because they are formed from the fusion of embryonic myoblasts.
Answer:
skeletal muscle cells can have multiple nuclei
Explanation:
This is because they are formed from the fusion of embryonic myoblasts.
14. Earthworms are crucial for forming soil. As they search for food by digging tunnels,
they expose rocks and minerals to the effects of weathering. Over time, this process
creates new soil. Worms are not the only living things that help to create soil. Plants
also play a part in the weathering process. As the roots of plants grow and seek out
water and nutrients, they help to break large rock fragments into smaller ones. Have
you ever seen a plant growing in a sidewalk? As the plants grows, its roots spread into
tiny cracks in the sidewalk. These roots apply pressure to the cracks, and, over time,
the cracks become larger, ice wedging can occur more readily. As the cracks expand,
more water can flow into them. When the water freezes, it expands and presses against
the walls of the cracks, which makes the cracks larger. Over time, the weathering
caused by water, plants, and worms help to form soil. QUESTION: Ice wedging, as
described in the passage, is an example of which of the following?
A mechanical weathering
B. Oxidation
C. chemical weathering
D. Hydrolysis
Ice wedging, as described in the passage, is an example of mechanical
weathering.
Mechanical weathering is also known as physical weathering and it
involves the breaking of rock into smaller particles without causing changes
in the chemical properties.Mechanical weathering is usually carried through
physical processes such as freezing and thawing etc.
In this scenario, we were told that water freezes, expands and presses
against the walls of the crack thereby breaking into smaller parts which is a
physical process hence mechanical weathering being present.
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Transverse waves move particles back and forth along the same direction in which the waves travel.
True false question.
True
False
Answer:
False, I am pretty sure.
Explanation:
Transverse waves are always characterized by particle motion being perpendicular to wave motion. ... As a sound wave moves from the lips of a speaker to the ear of a listener, particles of air vibrate back and forth in the same direction and the opposite direction of energy transport.
The maximum speed with which an 1000 kg car makes a 180-degree turn is 10 m/s. The radius of the circle through which the car is turning is 24 m. Determine the force of friction and the coefficient of friction acting upon
the car.
compare and contrast a transverse wave and a compressional wave Give an example for each type
Answer:
Transverse waves oscillate perpendicular to the direction of the wave (e.g. any electromagnetic wave like radiowaves, x-rays...) whilst compressional waves oscillate in the same direction of the wave (e.g. sound waves)
Explanation:
3. How much power does an electric light installation draw at 120 V if it creates a current of 0.8 amps?
O A. 32 watts
O B. 120 watts
Q C. 48 watts
D. 96 watts
Answer:D
Explanation:
R =
V
I
=
120 volt
0.8 ampere
= 150 ohm (Ω)
P = V × I
= 120 volt × 0.8 ampere
= 96 watt (W)
An electric light installation can draw Power of 96 Watt at 120 V if it creates a current of 0.8 amps
What is electric power ?Electric power is the rate of electric energy transfer by an electric circuit per unit time . It is denoted by P and measured using the SI unit of power that is Watt (W)
since, Electric Power = voltage * current
Power = 120 V * 0.8 A
Power = 96 Watts
An electric light installation can draw Power of 96 Watt at 120 V if it creates a current of 0.8 amps
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Which statement is true for a series circuit
Answer: they have one path to flow
Explanation: share the same current