4. A 5.00-kg sled starts at rest and accelerates down a 45.0° incline. The coefficient of
kinetic friction between the mass and the incline is .185.
a) What is the value of the of the acceleration of the sled
Answer: [tex]5.64\ m/s^2[/tex]
Explanation:
Given
mass of sled m=5 kg
Elevation [tex]\theta =45^{\circ}[/tex]
[tex]\mu _k=0.185[/tex] (coefficient of kinetic friction)
Friction will oppose the motion of the sled while sled weight sin component helps it to move down the incline
[tex]W\sin\theta-F_r=ma\\where\\W=weight(mg)\\F_r=Friction(\mu_kmg\cos\theta)\\a=acceleration[/tex]
Substituting values
[tex]mg\sin \theta-\mu_kmgcos\theta=ma\\g\sin \theta-\mu_kg\cos \theta=a\\a=g(\sin 45^{\circ}-0.185\times \cos 45^{\circ})\\a=5.64\ m/s^2[/tex]
B. Which of these uses the most power? Explain your answer.
1) 160 J of work in 8 seconds
2) 80 J of work is 4 seconds
3) 180 J of work in 9 seconds
Answer:
p=w/t
160/8=20
80/4=20
180/9=20
...so..all these uses equal power
Which of the following is a layer of the solid Earth? A. convecting mantle B. Ring of Fire C. biosphere D. atmosphere
Answer:
It's a cause that's the last layer
Answer:
I believe the answer is A
Explanation:
It is not the ring of fire because the ring of fire is the result of tectonic plates moving. It is not the biosphere because biosphere is the regions of the surface. The convecting mantle is the solid layer of the Earth because the mantle is mostly solid. The atmosphere is a solid plastic layer of the Earth. I hope this helps.
A boxer pushes on a 25 kg heavy bag which is attached to the ceiling until it makes an angle of 36 degrees to the vertical. How much force must the boxer exert on the bag?
Answer:
198.20 N
Explanation:
Given that,
Mass of a heavy bag, m = 25 kg
The bag is attached to the ceiling until it makes an angle of 36 degrees to the vertical.
We need to find the force must the boxer exert on the bag. The force acting on the bag is given by :
[tex]F=mg\cos\theta\\\\=25\times 9.8\times \cos(36)\\\\=198.20\ N[/tex]
So, the required force is 198.20 N.
What is the momentum of a 120 pound bicyclist that is traveling at 25 mph?
According to the law of conservation of energy, mechanical energy can be changed to heat energy.
Answer:
The answer to this question is given below in this explanation section.
Explanation:
" law of conservation of energy"
The law of conservation of energy states that energy can neither be created nor destroyed only converted from one form of energy into another.This mean that a system always has a same account of a energy,unless it is added from the outside.This is particularly confusing in the case of non conversation forces,where energy is converted from ,mechanical energy into thermal energy.but the overall energy does remain the same.The only way to use energy is to transform energy from one form to another.
The amount of energy in any system than it is determined by the following equation.
Ut=Ui +W+Q
Ut is the total internal energy of a system.Ui is the initial internal energy of a system.W is the work done by or on the system.Q is the heat added to or removed by the system.It is also possible to determined the change in internal energy of the system using the equation.
ΔU=W+Q
The mechanical energy of a system increases provided their is no loss of energy due to friction.The energy would transform to kinetic energy when the speed is increasing.Te mechanical energy of a system remain constant provided their is no loss of energy due to friction.
The law of conversation of energy which say that in a closed system total energy is conserved that is it constant.
KE1 + PE1=KE2+PE2
Which of the following statements about infrared telescopes is NOT true?
a. They are typically operated at lower temperatures.
b. They are especially helpful for viewing cool or obscured astronomical objects.
c. They were first built in the 1960s.
d. They are often placed on mountaintops.
e. They do not work well at high altitudes.
Answer:
a. They are typically operated at lower temperatures.
a. They are typically operated at lower temperatures.b. They are especially helpful for viewing cool or obscured astronomical objects.
State the lows of reflection
Answer:
The law of reflection states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.
Explanation:
Answer: The law of reflection states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.
A man standing on top of a 30 m tall building throws a brick downwards with a velocity of 12 m/s. Determine the speed of the brick just before it hits the ground.
Answer:
27.1m/s
Explanation:
Given parameters:
Height of the building = 30m
Initial velocity = 12m/s
Unknown:
Final velocity = ?
Solution:
We apply one of the kinematics equation to solve this problem:
v² = u² + 2gh
v is the final velocity
u is the initial velocity
g is the acceleration due to gravity
h is the height
v² = 12² + (2 x 9.8 x 30)
v = 27.1m/s
A tractor trailer truck traveling at a speed of 105 feet/second skids to a stop in 12 seconds. Determine the skidding distance of the truck.
Please help.
Answer:
1260ft
Explanation:
Given parameters:
Speed = 105ft/s
Time = 12s
Unknown:
Skidding distance of the truck = ?
Solution:
To solve this problem:
Distance = speed x time
Now insert the parameters and solve;
Distance = 105 x 12 = 1260ft
Transfer of charge by touching is called... induction or conduction?
Answer:
Transfer of charge by touching is called conduction.
A 2.0 kg block is pulled across a horizontal surface by a 15 N force at a constant velocity.a. What is the net force acting on the block?
Answer:
0
Explanation:
the block is being pulled at a constant velocity meaning it has no acceleration. the rule is fnet=mass x acceleration so if theres no acceleration there is no force net!
A block of mass 2 kg is pulled across a surface with a force of 15 N then the net force acting on the block is 0.
What is Force?A force is an effect that can alter an object's motion according to physics. A force might cause an object has mass to accelerate when it changes its velocity, for, us when it moves away from rest. An obvious way to describe force is in terms of push or pull. A force is a vector quantity since it has equal magnitude and direction. It is calculated using the newton SI unit (N). Force is denoted by the letter F.
The net force exerted by an object was equal to the speed at which its velocity varies over time, according to Newton's second law in its original formulation.
The block has no acceleration because it is being pushed at a constant speed. If there is no acceleration, there is no force net because the formula is net force =mass × acceleration.
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What is the electric potential at a distance of 1.2 m from a 7.5 UC point charge?
5.6 x 104 v
8.1 x 104 V
5.6 % 1010 V
8.1 x 1010 V
Answer:
5.6x10^4
Explanation:
use the equation V=kq/d
k is the constant 8.99x10^9
V=(8.99x10^9)q/d
q is the charge, 7.5 micro coulombs, but to get coulombs, multiply by 10^-6
V=(8.99x10^9)(7.5x10^-6)/d
And from the problem, we know that the distance is 1.2 meters
V=(8.99x10^9)(7.5x10^-6)/1.2
This simplifies to 5.6x10^4
The electric potential is 5.6 x 10⁴ v.
To find the electric potential the distance = 1.2 m
Charge q = 7.5 UC
What is electric potential and find the value?The amount of work needed to move a unit charge from the known point to some unknown point against the electric field is said to be electric potential.
Formula of an electric potential is
V = k ( q/r) volt
V - electric potential
k - Coulomb constant (8.99x10^9)
q - charge
r- distance of separation
V = (8.99x10⁹) (q/d)
q = 7.5 UC ( micro coulomb) 10⁻⁶ C
V=(8.99x10⁹)(7.5x10⁻⁶)/d
Substituting the values,
V=(8.99x10⁹)(7.5x10⁻⁶)/1.2
V = 5.6x10⁴ v
Thus, option A is correct.
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If you and your friend are playing tug of war and both are you are pulling with the same amount of force. What will happen?
Answer:
Nothin will move, it will stay the same since no force is greater than the other. it's "the same amount of force" which also means an equal amount of force
Explanation:
The forces are only equal if there is no acceleration (which in the game of tug of war, accelerating yourself and your opponent is the idea). If the force on the rope and the ground are both equal either nothing moves or some other force is being applied in the system.
Hope this helped!
Sam scored 98, 25, 105, 62 and 65 runs in 5 matches. What was the average score per match?
Answer:
71
Explanation:
please help, brainest if correct
Answer: B
Its b increased risk of disease
Please help ASAP I’ll give brainly and 10 points
Which of the following can sometimes be zero for a moving body i average velocity ii distance travelled iii average speed iv displacement
Answer:
displacement can be zero...because it only care about initial and final positionshow would a position-time function look like for linearly increasing negative velocity regions?
Answer:
Hmmm
Explanation:
Here what I know... If a function gives the position of something as a function of time, the first derivative gives its velocity, and the second derivative gives its acceleration. So, you differentiate position to get velocity, and you differentiate velocity to get acceleration. where t is in seconds and H(t) is in inches.
Does this help?
How much water is displaced by a solid object with a volume of 9 cm3 that is completely submerged in the water?
Given :
An object with a volume of 9 cm³ is completely submerged in the water.
To Find :
How much water is displaced by the object.
Solution :
According to Archimedes' principle, the amount of volume displaced of fluid when an object is fully and partially submerged into that is equal to the volume of the object below the surface of liquid.
Now, it is given that object is fully submerged into water.
Therefore, volume of water displaced by the object is 9 cm³.
Can someone do this pls! I’ll give you brainilest and all my points!
Answer:
15N South
Explanation:
It is 15N South because the two 15N cancel out each other and then you subtract 5N from the 20N and then you get left with 15N. and the 20N is bigger and it is going South.So the answer is 25N south.
Answer:
the answer would be 15N south
A force has both______ and _______. Question 3 options: Magnitude & Direction Direction & Motion Speed & Impact Speed and Direction
Answer:
A force has both Direction and Motion.
Explanation:
For example, when finding acceleration you take the time and divided it by distance. If the thing you are measuring is going in the positive direction, the acceleration will be positive and if it is going in the negative direction the acceleration will be negative.
Magnitude and Direction
Explanation:
Force is a Vector Quantity
As learned in an earlier unit, a vector quantity is a quantity that has both magnitude and direction. To fully describe the force acting upon an object, you must describe both the magnitude (size or numerical value) and the direction.
Two objects are shown below. One is neutral and the other is negative. What do you predict would happen?
Answer:
The body becomes a positive charged body.
Explanation:
Given that two objects are shown below. One is neutral and the other is negative. What do you predict would happen?
According to the law of static electricity, like charges repel each other while unlike charges attract each other.
Since one of the object is neutral and the other one is negative, there will neither attraction nor repulsion between them.
Also, according to Electrostatic induction, the neural body can be charged and becomes positive.
The negative body will attract all the positive charges to its side, and repel all the negative charges to the other side. If the body is touched at the other end, the whole negative charges will be earthed and the body will become a positive body.
What type of system is a black hole? Explain how you know.
Answer:
A black hole is a region of spacetime where gravity is so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it.[1] The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.[2][3]
The boundary of the region from which no escape is possible is called the event horizon. Although the event horizon has an enormous effect on the fate and circumstances of an object crossing it, according to general relativity it has no locally detectable features.[4] In many ways, a black hole acts like an ideal black body, as it reflects no light.[5][6] Moreover, quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is on the order of billionths of a kelvin for black holes of stellar mass, making it essentially impossible to observe directly.
Objects whose gravitational fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace.[7] The first modern solution of general relativity that would characterize a black hole was found by Karl Schwarzschild in 1916, although its interpretation as a region of space from which nothing can escape was first published by David Finkelstein in 1958. Black holes were long considered a mathematical curiosity; it was not until the 1960s that theoretical work showed they were a generic prediction of general relativity. The discovery of neutron stars by Jocelyn Bell Burnell in 1967 sparked interest in gravitationally collapsed compact objects as a possible astrophysical reality.
Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. After a black hole has formed, it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses (M☉) may form. There is consensus that supermassive black holes exist in the centers of most galaxies.
The presence of a black hole can be inferred through its interaction with other matter and with electromagnetic radiation such as visible light. Matter that falls onto a black hole can form an external accretion disk heated by friction, forming quasars, some of the brightest objects in the universe. Stars passing too close to a supermassive black hole can be shred into streamers that shine very brightly before being "swallowed."[8] If there are other stars orbiting a black hole, their orbits can be used to determine the black hole's mass and location. Such observations can be used to exclude possible alternatives such as neutron stars. In this way, astronomers have identified numerous stellar black hole candidates in binary systems, and established that the radio source known as Sagittarius A*, at the core of the Milky Way galaxy, contains a supermassive black hole of about 4.3 million solar masses.
On 11 February 2016, the LIGO Scientific Collaboration and the Virgo collaboration announced the first direct detection of gravitational waves, which also represented the first observation of a black hole merger.[9] As of December 2018, eleven gravitational wave events have been observed that originated from ten merging black holes (along with one binary neutron star merger).[10][11] On 10 April 2019, the first direct image of a black hole and its vicinity was published, following observations made by the Event Horizon Telescope in 2017 of the supermassive black hole in Messier 87's galactic centre.[12][13][14]
Blackness of space with black marked as center of donut of orange and red gases
The supermassive black hole at the core of supergiant elliptical galaxy Messier 87, with a mass about 7 billion times that of the Sun,[15] as depicted in the first false-colour image in radio waves released by the Event Horizon Telescope (10 April 2019).[16][12][17][18] Visible are the crescent-shaped emission ring and central shadow,[19] which are gravitationally magnified views of the black hole's photon ring and the photon capture zone of its event horizon. The crescent shape arises from the black hole's rotation and relativistic beaming; the shadow is about 2.6 times the diameter of the event horizon.[12]
Schwarzschild black hole
Simulation of gravitational lensing by a black hole, which distorts the image of a galaxy in the background
Gas cloud being ripped apart by black hole at the centre of the Milky Way (observations from 2006, 2010 and 2013 are shown in blue, green and red, respectively).[20]
Which tool can easily separate sand and iron filings?
O oil
O magnet
O water
Answer:
A magnet would be the answer
Which lighting source has lower energy costs and a longer life but can be dangerous?
a. fluorescent
b. laser
c. incandescent
d. neon
Answer: I'm like 98% sure it's fluorescent cause it's got mercury
Explanation:
help!! what are the blanks???
The earth receives energy from the sun in one day than all the energy consumed by humans in one year.
Amount of energy received from the sun
The sun provides around 174 petawatts of energy to Earth, of which 89 petawatts is absorbed by the planet.
The Global energy consumption is roughly 15 terawatts annually.
Thus, we can conclude that, the earth receives energy from the sun in one day than all the energy consumed by humans in one year.
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A current of 8 A flows through a conductor. The number of electrons passing through the conductor in each second will be
Answer:
8=3×1019 electrons per second.
Explanation:
Answer:
here
Explanation:8=3×1019 electrons per second.
If the sun were to collapse into a black hole, what would the radius be?
Answer:
If the Sun, with its mass of 1 MSun, were to become a black hole the Schwarzschild radius would be about 3 kilometers; thus, the entire black hole would be about one-third the size of a neutron star of that same mass
Answer:
It would be 1/3rd size of a neutron star
Explanation:
the Schwarzschild radius would be about 3 kilometers; thus, the entire black hole would be about one-third the size of a neutron star of that same mass.
a skydiver has a mass of 50.5 kg what is the force of weight on the sky diver?
F= _N
Answer:
The answer is 494.9 N
Explanation:
I got this same question, and it worked for me! Hope this helps <3