Answer:
(D) x = 93.8 m
Explanation:
v^2 = v0^2 + 2ax
(20 m/s)^2 = (5 m/s)^2 + 2(2 m/s^2)x
Solving for x,
x = 93.8 m
A 700-gram grinding wheel 22.0 cm in diameter is in the shape of a uniform solid disk. (We can ignore the small hole at the center.) When it is in use, it turns at a constant 215 rpm about an axle perpendicular to its face through its center. When the power switch is turned off, you observe that the wheel stops in 50.0 s with constant angular acceleration due to friction at the axle.
What torque does friction exert while this wheel is slowing down?
Solution :
Given :
Mass of grinding wheel, m = 700 g
= 0.7 kg
Diameter of the grinding wheel, d = 22 cm
= 0.22 m
Radius of the grinding wheel, r = 0.11 m
Initial angular velocity of grinding wheel, [tex]$\omega_0$[/tex] = 215 rpm
[tex]$=215 \ rpm \times \frac{2 \pi \ rad}{1 \ rev}\times \frac{1 \ min}{60 \ s}$[/tex]
where, [tex]$\pi = \frac{22}{7}$[/tex]
Time taken to stop, t = 50 s
Final angular velocity is [tex]$\omega$[/tex] = 0
Angular acceleration of the grinding wheel is given by :
[tex]$\alpha = \frac{\omega-\omega_0}{t}$[/tex]
[tex]$=\frac{0-215 \ rpm \times \frac{2 \pi \ rad}{1 \ rev}\times \frac{1 \ min}{60 \ s}}{50 \ s}$[/tex]
[tex]$=-0.45 \ rad/s^2$[/tex]
Magnitude of the angular acceleration of grinding wheel [tex]$\alpha$[/tex] [tex]$=-0.45 \ rad/s^2$[/tex]
Moment of inertia of the grinding wheel (solid disk),
[tex]$I=\frac{1}{2}mR^2$[/tex]
[tex]$=\frac{1}{2} \times 0.7 \times 0.11^2$[/tex]
[tex]$=4.235 \times 10^{-3} \ kgm^2$[/tex]
Torque exerted by friction while the wheel is slowing down is
[tex]$\tau = I \alpha$[/tex]
[tex]$=4.235 \times 10^{-3} \times 0.45$[/tex]
[tex]$=1.90 \times 10^{-3} \ Nm$[/tex]
government as an academic field of study
Answer: True
Explanation:
Government as an academic field of study refers to the study of political institutions, processes and theories taught in schools, colleges and higher institution of learning. It is called Political Science in higher institution.
has been proposed to use an array of infrared telescopes spread over thousands of kilometers of spaceto observe planets orbiting other stars. Consider such an array with an effective diameter of 6000 km, whichobserves infrared radiation at a wavelength of 10m. If it is used to observe a planet orbiting the star 70Virginis, which is 59 light years from our solar system, what is the size of the smallest details that the arraymight resolve on the planet
Answer:
[tex]\triangle x=1.135 *10^9km[/tex]
Explanation:
From the question we are told that:
Diameter of array[tex]d=6000km \approx 6000*10^3[/tex]
Infrared wavelength [tex]\lambda =10m[/tex]
Distance of planet [tex]d=59 light\ years \approx 55.82*10^{16}m[/tex]
Generally the equation for Diffraction is mathematically given by
[tex]sin\theta =1.22\frac{\lambda}{D}[/tex]
Given that
[tex]sin\theta=\frac{\triangle x}{R}[/tex]
Therefore
[tex]\frac{\triangle x}{R}=1.22\frac{\lambda}{D}[/tex]
[tex]\triangle x=1.22\frac{R \lambda}{D}[/tex]
[tex]\triangle x=1.22\frac{10 *55.82*10^{16}}{6000*10^3}[/tex]
[tex]\triangle x=1.135 *!0^1^2m[/tex]
[tex]\triangle x=1.135 *10^9km[/tex]
PLEASE HELP
Which of the following are examples of gravity in action? Select all that apply.
A. an earthquake
B. a planet orbiting the sun
C. a ball flying through the air
D. precipitation falling to Earth
Consider the situation in which three identical spheres of clay are launched simultaneously, one along each possible path. All three spheres of clay are launched with the same initial linear speed and collide with the rod at the same time. The time of collision with the rod for each sphere is time t0. Which of the following predictions is correct about the motion of the system containing the rod and all three spheres of clay immediately after the collision?
a. The system will rotate in the clockwise direction with a constant angular speed.
b. The system will rotate in the counterclockwise direction with a constant angular speed.
c. The system will rotate in the clockwise direction with a changing angular speed.
d. The system will rotate in the counterclockwise direction with a changing angular speed.
Answer:
a. The system will rotate in the clockwise direction with a constant angular speed.
Explanation:
As all the clay is identical sphere and there will be hence same mass 'm' for all three clay spheres. Now their identical speed 'v' and collision time [tex]$'t_0'$[/tex] are also same. So all the spheres will exert same force F on the rod.
[tex]$f=\frac{mv}{t_0}$[/tex]
Force exerted by the clay Z on rod is passing through pivot, so no torque will be produced.
Now clay X will collide at near distance from pivot than that of clay Y.
So clay Y will produce more torque than clay X. So clay Y will give more clockwise torque. So rod will rotate clockwise.
Now in any impact because net force and net torque are zero (because in impact torque and force occurs in equal and opposite pairs). So net angular momentum will be conserved and hence angular speed will be constant.
Therefore it is clear that option (a) is correct.
The fictional rocket ship Adventure is measured to be 65 m long by the ship's captain inside the rocket.When the rocket moves past a space dock at 0.5c. As rocket ship Adventure passes by the space dock, the ship's captain flashes a flashlight at 1.20-s intervals as measured by space-dock personnel.
Required:
How often does the flashlight flash relative to the captain?
Answer:
1.04 s
Explanation:
The computation is shown below:
As we know that
t = t' × 1 ÷ (√(1 - (v/c)^2)
here
v = 0.5c
t = 1.20 -s
So,
1.20 = t' × 1 ÷ (√(1 - (0.5/c)^2)
1.20 = t' × 1 ÷ (√(1 - (0.5)^2)
1.20 = t' ÷ √0.75
1.20 = t' ÷ 0.866
t' = 0.866 × 1.20
= 1.04 s
The above formula should be applied
A block and tackle of 6 pulleys is used to raise a load of 300 newton steadily through a height of 30 meters. If the work done against friction is 2000j calculate the work done by effort?
Answer:
W = F * S = 300 N * 30 m = 9000 Joules
This is the work out of the system regardless of how the pulleys are arranged
Conservation of energy tells that
Work Out = Work In - Work done by friction
So Work In = 9000 J + 2000 J = 11000 J The work input to the system
What kind of story would a Romantic audience find MOST appealing?
A. science fiction or futuristic worlds
B. a comedy or something light-hearted
C. one based on Christian morals and piety
D. something where a person disappears in nature
A sprinter accelerates at 8mps, he weights 850 grams. What
force is he exerting?
PLZ help 10 points!!! space question!
Answer:
3 i think
Explanation:
The owner of a van installs a rear-window lens that has a focal length of -0.304 m. When the owner looks out through the lens at a person standing directly behind the van, the person appears to be just 0.237 m from the back of the van, and appears to be 0.343 m tall. (a) How far from the van is the person actually standing
Answer:
[tex]p =-1.03[/tex]
Explanation:
From the question we are told that:
Focal length of lens [tex]f=-0.304 m[/tex]
Image distance [tex]q=0.237 m[/tex]
Height of image [tex]H_i=0.343[/tex]
Generally the lens equation is mathematically given by
[tex]\frac{1}{f} = \frac{1}{q} - \frac{1}{p}[/tex]
Where [tex]p[/tex] is Subject
[tex]p = \frac{(qf) }{(f - q)}[/tex]
[tex]p = \frac{(-0.237)(-0.304)) }{((-0.304) - (0.237))}[/tex]
[tex]p =-1.03[/tex]
Therefore the distance between the person and the car is
[tex]p =-1.03[/tex]
On Apollo Moon missions, the lunar module would blast off from the Moon's surface and dock with the command module in lunar orbit. After docking, the lunar module would be jettisoned and allowed to crash back onto the lunar surface. Seismometers placed on the Moon's surface by the astronauts would then pick up the resulting seismic waves.
Find the impact speed of the lunar module, given that it is jettisoned from an orbit 110 km above the lunar surface moving with a speed of 1600 m/s .
My Approach:
Ei = Ef
1/2*m*vi2 - (G*m*ME)/(radius of moon + orbital distance) = 1/2*m*vf2 - (G*m*ME)/r
=> (0.5 * m * 16002) - (6.67 * 10-11 * 7.35*1022 * m/(1737.4*103 +180*103) = (0.5*m*v^2) - (6.67*10-11 * 7.35*1022 * m/(1737.4*103 )
Answer:
Following are the solution to the given question:
Explanation:
For crashing speed, we can use energy conservation:
kinetic energy [tex]= \frac{1}{2}\times m \times v^2[/tex]
potential energy [tex]= -\frac{GMm}{r}[/tex]
moon mass[tex]= 7.36\times 10^{22} \ kg[/tex]
Radius[tex]= 1738\ km[/tex]
[tex]\to (K + U) \ orbit = (K + U)\ crash\\\\\to \frac{1}{2}\times m \times v_o^2 - \frac{GMm}{(1738000 + 110000)} \\\\ \to \frac{1}{2}\times m \times vc^2 - \frac{GMm}{1738000}[/tex]
Calculating the mass drop for the leave:
[tex]\to \frac{vo^2}{2} - \frac{GM}{1848000}\\\\ \to \frac{vc^2}{2} - \frac{GM}{1738000}[/tex]
Solve the value for
[tex]vc = \sqrt{(vo^2 +2\times GM \times(\frac{1}{1738000} - \frac{1}{1848000}))}\\\\vc = \sqrt{(1600^2 +2\times 6.67\times 10^{-11} \times 7.36 \times 10^{22}\times (\frac{1}{1738000} - \frac{1}{1848000}))}\\\\vc = 1701 \ \frac{m}{s}\\\\[/tex]
The approach is correct but misrepresented in replacing 180 km instead of 110 km.
Which type of electromagnetic radiation is used to keep food warm?
O A. Infrared radiation
O B. Visible light
O C. Gamma rays
D. X-rays
Answer:
A. infrared
Explanation:
Heat lamps used to keep foods warm are infrared on the light spectrum
8. Which element will most likely form an ionic bond with chlorine?
A. O
B.N
C.S
D.K
⦁ Determining the magnetic flux, A rectangular piece of stiff paper measures 10 cm x 5 cm. You hold the piece of paper in a uniform magnetic field that has a magnitude of 4.0 x10-3 T For each situation below, - sketch a diagram showing the magnetic field and the paper, - determine the magnitude of the magnetic flux through the paper, when the magnitude of the flux is (a) maximized (b) minimized (c) halfway between its maximum and minimum value, when the angle between the magnetic field lines and the area normal vector is 300
Answer:
jguewjdofe
Explanation:
a student throws a 140 g snowball at 8.5 m/s at the side of a schoolhouse, where it hits and sticks. what is the magnitude of the average force on the wall if the duration of the collision is .16 s?
Answer:
7.4375N
Explanation:
According to Newtons second law
F = ma
m is the mass = 140g = 0.14kg
Get the acceleration
v = u + at
8.5 = 0+0.1a
a = 8.5/0.16
a = 53.125m/s²
Get the required force
F = 0.14 * 53.125
F = 7.4375N
Hence the magnitude of the average force on the wall is 7.4375N
What are applications of zeroth law of thermodynamics?
Answer:
Applications of zeroth law of thermodynamics:
1. When we get very hot food, we wait to make it normal. In this case, hot food exchanges heat with surrounding and brings equilibrium.
2. We keep things in the fridge and those things come equilibrium with fridge temperature.
3. Temperature measurement with a thermometer or another device.
4. In the HVAC system, sensors or thermostats are used to indicate temperature. It always comes in a thermal equilibrium with room temperature.
5. If you and the swimming pool you’re in are at the same temperature, no heat is flowing from you to it or from it to you (although the possibility is there). You’re in thermal equilibrium.
A body starts from rest and travels ‘s’ m in 2nd second, than acceleration is.
1) 2s m / s2 2) 3 s m / s2 3) 23 s m / s2 4) 32 s m / s2
Answer:
3m
Explanation:
11.Electricity is made at a power plant by huge
(C). Coil
(D). Wire
(A). Motor
(B). Generator
How much energy must the brakes absorb to bring a 1200kg car from 30m/s to 15 m/s?
an object is moving at 60m/s and has a mass of 5 kg what is its momentum
Answer:
300
Explanation:
the momentum is 300
p=mv
p=5×60
5×60 =300
A heating coil operates on 220 V if it draws 15.0 A. Find it's resistance
Answer:
R ≈ 15 ohms
Explanation:
Using ohm's law equation,
I = V/R, to solve for the resistance of the heating coil.
R = V/I
Known:
V = 220 v = 220 kgm^2s^-3A^-1
I = 15 A
Unknown:
R =?
Solution:
R = (220 kgm^2s^-3A^-1)/ 15.0 A
R = 14.6 kgm^2s^-3A^-2
R ≈ 15 kgm^2s^-3A^-2
R ≈ 15 ohms
3. An object has 90,000 J Kinetic energy and is moving at 12m/s. What is the objects mass?
what is the relationship between Force, area and mass
Answer:
F=ma
Explanation:
Force is equal to mass multiplied by area
Force= mass × area
In turn the formula can be twisted so
Force/mass= area
Force/area= mass
Answer:
It states that the rate of change of velocity of an object is directly proportional to the force applied and takes place in the direction of the force. It is summarized by the equation: Force (N) = mass (kg) × acceleration (m/s²). Thus, an object of constant mass accelerates in proportion to the force applied.
what term is used to describe the block of organs (heart, lungs, liver, kidneys and spleen) that are removed during the autopsy?
The term used to describe the block of organs that are removed during the autopsy is Thoracic organs.
The organs that are removed during autopsy include:
Thoracic organs;Cervical organs, and Abdominal organsThe thoracic cavity contains organs and tissues that function in the respirator, cardiovascular, nervous and digestive system.
These thoracic organs include the following;
heart, lungs, liver, kidneys and spleen.Thus, we can conclude that the term used to describe the block of organs that are removed during the autopsy is Thoracic organs.
Learn more here:https://brainly.com/question/25087653
A long time ago on top of a mountain, the rocks were jagged and pointy. Over thousands of years, the rocks have become smooth.
What process explains this change?
pulling
weathering
depositing
eroding
Answer:
Eroding
Explanation:
A long time ago on top of a mountain, the rocks were jagged and pointy. Over thousands of years, the rocks have become smooth. The process explains this change is Eroding. Hence, Option D is the correct answer.
What is Erosion?Erosion is a process of eroding some solids by wind, water and other natural agent while weathering is breaking down of rocks, soil and minerals.
The different types of Erosion includes,
Gully erosionsheet erosionRill erosionsheet erosionThese factors that will contribute to the rate of water erosion includes the climatic factor (rainfall amount, intensity and frequency).
TopographySoil coverSoil propertiesMass wasting erosion if it is a type of erosion but not by water. It is a type of erosion that is generated mainly by the effect of gravity. It is also called mass movement, in which the material detaches from an inclined surface and falls as a result of gravity.
Here, A long time ago on top of a mountain, the rocks were jagged and pointy. Over thousands of years, the rocks have become smooth. The process explains this change is Eroding. Hence, Option D is the correct answer.
Learn more about Erosion,
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How long will it take you to drive, at 80km/h a distance of 275km?
Answer:
3.44 s
Explanation:
speed=distance/time
=>t = s/v
=> t = 275/80
= 3.437.. s
A ray diagram is shown. A tree acts as the object further than 2 F away from a biconvex lens. The distance between 2 F and the object is labeled W. The distance between F and 2 F is labeled X. There I a light ray parallel to the principal axis is bent through F on the image side of the lens. There is a ray straight through the center of the lens. The rays intersect a point below the principle axis between F and 2 F on the image side of the lens and is closer to the principal axis than the object is tall. The intersect point is labeled Z and the distance between F and 2 F on the image side of the lens is labeled Y. Which letter represents the location of the image produced by the lens? W X Y Z
Answer:
Z
Explanation:
correct on edge
Answer: Z
good luck!
19. What is shape of BF3
Explanation:
The geometry of the BF 3 molecule is called trigonal planar (see Figure 5). The fluorine atoms are positioned at the vertices of an equilateral triangle. The F-B-F angle is 120° and all four atoms lie in the same plane.
Which type of wave displaces the particles of the medium parallel to the direction on which the wave travels?
Longitudinal waves
In a longitudinal wave the particles are displaced parallel to the direction the wave travels.