Answer:
a) Weight of Roommate = 481.4 N
b) μk = 0.34
Explanation:
a)
The force required to move the couch must be equal to the force of friction:
F = frictional force
F = μW
W = F/μ
where,
W = Total Weight of Couch and Roommate
F = Force Required start to move couch = 250 N
μ = coefficient of static friction between couch and floor = 0.43
Therefore,
[tex]W = \frac{250 N}{0.43}\\\\W = 581.4 N[/tex]
So, the total weight is given as:
W = Weight of Couch + Weight of Roommate
Weight of Roommate = W - Weight of Couch
Weight of Roommate = 581.4 N - 100 N
Weight of Roommate = 481.4 N
b)
Now, the force required to keep the couch moving can be given as equal to the kinetic friction force:
F = kinetic friction
F = μk*W
μk = F/W
where,
μk = coefficient of kinetic friction = ?
F = Force required to keep the couch moving = 200 N
Therefore,
μk = 200 N/581.4 N
μk = 0.34
If forces acting on an object are unbalanced, the object could experience a change in ________.
mass, speed, or direction
negative acceleration or mass
direction, mass, or both
speed, direction, or both
D) Speed, direction, or both
Mass doesn’t just CHANGE like that.
A ball of mass 4kg moving with a velocity of 20m/s collides with another ball of mass 15kg moving with a velocity of 15m/s in the same direction. Calculate the velocity of the 5kg ball if the collision is perfectly inelastic.
Answer:
velocity = 16.05 m/s
Explanation:
inelastic collision formula:
m1u1 + m2u2 = (m1 + m2)v
m1 = 4kg
u1 = 20m/s
m2 = 15kg
u2 = 15m/s
find v ?
m1u1 + m2u2 = (m1 + m2)v
(4×20) + (15×15) = (4+15)v
80 + 225 = 19v
305 = 19v
19v = 305
v = 305/19
v = 16.05 m/s
identical spheres are dropped from a height of 100 m above the surfaces of Planet X and Planet Y. The speed of the spheres as a function of time is recorded for each planet in the graph
above. Which planet exerts the greater force of gravity on the sphere, and what evidence supports this conclusion?
A Planet X because its line has the greater area under it.
Planet X, because its line has the greater slope
Planet Y. because it falls for the smaller amount of time
Planet Y because the object's final speed is greater
Answer:
B. Planet X, because its line has the greater slope.
Explanation:
In a speed graph, acceleration is slope. A greater slope means a greater acceleration. According to Newton's 2nd law (F=mg), a greater acceleration means a greater force.
Planet X exerts the greater force of gravity on the sphere, because its line has the greater slope. Hence option B is correct.
What is Gravitational Force ?Gravitational force is force of attraction between two masses. Gravitational force(F) between two bodies is directly proportion to the product of masses(m₁,m₂) of two bodies and inversely proportional to square of distance(r) between them. mathematically it is written as,
F ∝ m₁.m₂
F ∝ 1/r²
F = G m₁,m₂÷r²
where G is gravitational constant, whose value is 6.6743 × 10⁻¹¹ m³ kg-1s⁻².
Force is expressed in Newton N in SI unit. its dimensions are [M¹L¹T⁻²].
This is analogous with coulomb's law which gives force between two charges.
if a planet has greater gravitational force(force of gravity), then body falls with greater speed as compare to other planet which is having less force of gravity. we can see in case of planet X there is greater speed as compare to plane Y in short time. Hence option B is correct.
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You're driving a bumper car at a circus at
18 m/sec, and you hit another car that's at
rest. If you end up going at 6.0 m/sec, what
is the final speed of the other car, given
that both cars have 100.0 kg mass, you
have 80.0 kg mass, and the other person
has a mass of 70.0 kg?
Answer:
PLEASE MARK AS BRAINLIEST!!
Explanation:
ANSWER IS IN THE IMG BELOW
name three characteristics of sound
Consider a rigid 3-mass system ( with origin at the leftmost mass 1 kg) which can rotate about an axis perpendicular to the system. The mass are separated by rods of length 5m, so that the entire length is 10m. Find the x-coordinate of the center of the mass for the three-mass system with respect to the origin. Treat mass as particles. Answer in unit of m.
now consider a rotation axis perpendicular to the system and passing through the point Xo at distance 3.8 m from the leftmost mass 1kg. find the moment of inertia of the 3-mass system about the new axis. Answer in unit of kg.m^2
Answer:
1) x_{cm} = 5 m , 2) I = 168.32 kg m²
Explanation:
1) An important concept of center of mass is
[tex]x_{cm} = \frac{1}{M} \sum x_{i} m_{i}[/tex]
where M is the total mass of the system
Let's apply this equation to our case, suppose that all masses are equal and are worth 1 kg
[tex]x_{cm}[/tex] = ⅓ (1 0 + 1 5 + 1 10)
x_{cm} = 5 m
2) In this para indicates that there is an axis of rotation at the point xo = 3.8 m and they ask to calculate the moment inertia.
Let's use the parallel axes theorem
I = I_{cm} + M D
where I_{cm} is the moment of inertia with respect to the center of mass, D the distance between the two axes of rotation and M the total mass of the system
Let's look for the moment of inertia of the center of mass
[tex]I_{cm}[/tex] = 1 0 + 1 5² + 1 10²
I_{cm} = 125 kg m²
the total moment of inertia is
I = 125 + 3 3.8²
I = 168.32 kg m²
The moment of inertia of the 3-mass system about the new axis is 54.32 kgm/s².
We have three masses each of mass = 1kg such that they are in line with mass m at origin, m at 5m and m at 10m
(a) The center of mass:
[tex]X=\frac{m_1x_1+m_2x_2+m_3x_3}{m_1+m_2+m_3} \\ \\ X =\frac{ 1*0+1*5+1*10}{1+1+1}\\ \\ X = 5m[/tex]
Hence the center of mass of the system is at x = 5m.
(b) The moment of inertia about the axis passing through x = 3.8m
from the parallel axis theorem:
[tex]I = I_{cm} + Md^2[/tex]
where, [tex]I_{cm}[/tex] is the moment of inertial along an axis passing through the center of mass of the system, M is the total mass of the system and d is the distance of the given axis from center of mass.
M = 3kg
d = 5 - 3.8 = 1.2m
[tex]I_{cm}=1*5^2+1*0+1*5^2\\\\ I_{cm}=50 kgm/s^2[/tex]
Md² = 3×(1.2)²
Md² = 4.32 kgm/s²
I = 50 + 4.32
I = 54.32 kgm/s² is the moment of inertial about the given axis.
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What are some ways that the Greeks demonstrated their passion for public life?
Answer:
The Greeks had drama and arts competitions that were considered very popular, and important in society.
Explanation:
hope it helps!
Consider a car engine running at constantspeed. That is, the crankshaft of the en-gine rotates at constant angular velocity whileeach piston moves back-and-forth in its cylin-der according to the rules of simple harmonicmotion.2030 rpm6.95 cmSuppose the two extremal positionsxmaxandxminof a piston are 6.95 cm from eachother.When the crankshaft of the engine rotatesat 2030 rpm (revolutions per minute), what isthe maximal speed|v|maxof the piston?Answer in units of m/s.
Answer:
The value is [tex]|v| = 7.39 \ m/s[/tex]
Explanation:
From the question we are told that
The angular speed is [tex]w = 2030 \ rpm = \frac{2030 * 2 * \pi }{ 60} = 212.61 \ rad/s[/tex]
The distance between the minimum and maximum external position is [tex]d = 6.95 \ cm = 0.0695 \ m[/tex]
Generally the amplitude of the crank shaft is mathematically represented as
[tex]A = \frac{d}{2}[/tex]
=> [tex]A = \frac{0.0695}{2}[/tex]
=> [tex]A = 0.03475 \ m[/tex]
Generally the maximum speed of the piston is mathematically represented as
[tex]|v| = A * w[/tex]
=> [tex]|v| = 0.03475 * 212.61[/tex]
=> [tex]|v| = 7.39 \ m/s[/tex]
a passenger of mass m on a Ferris wheel moves in a vertical circle of radius r with constant speed v assuming that the seat remains upright during the motion which is true about the force the seat exerts on the passenger at the top of the circle
the upward force is equal in magnitude to the passenger's weight
the upward force is greater in magnitude than the passenger's weight
the upward force is smaller in magnitude than the passenger's weight
the upward force is zero
Answer:
the upward force is equal to the passenger weight
The answer that is the truth about the force that the seat exerts on the passenger is the upward force is equal in magnitude to the passenger's weight.
Why the upward force is equal in magnitude to weight
The acting forces on the body has been said to be vertical. This implies that the upward force and the downward force of gravity are the same.
Using the second law of Isaac Newton, the downward direction of the forces would be ascertained.
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before leaving earth, the mass if an astronaut is measured to be 60kg. the astronaut lands on the moon and measures the acceleration of gravity to be 1.6 m/s^2. what is the mass of the astronaut at moon?
Answer:
The answer is 2,475$+948= add you will get the answer rn
The weight we experience on a surface is the product of our mass and acceleration due to gravity on that surface. The mass of the astronaut in earth was 60 kg . Then his mass at moon will be 9.76 kg.
What is gravitational force ?The gravitational force is the force by which an object attracts other objects into its center of mass. Earth attracts every objects into its center. That why we are all standing on the ground.
The weight we experience on earth is due to the gravity. That is the product of mass and acceleration due to gravity of a planet is the weight on the planet.
The weight of astronaut in earth = 60 kg
acceleration due to gravity on earth = 9.8 m/s²
mass = 60/9.8 m/s² = 6.19 kg
Acceleration due gravity on moon = 1.6 m/s²
then weight on moon = 1.6 m/s² ×6.19 kg = 9.7 kg.
Therefore, the weight of the astronaut in moon will be 9.7 kg.
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A stiuden goes for a bike ride ayt 20 meters
Two disks are rotating about the same axis. Disk A has a moment of inertia of 3.4 kg m^2 and an angular velocity of 7.2 rad/s. Disk B is rotating with an angular velocity of -9.8 rad/s. The two disks are then linked together without the aid of any external torques, so that they rotate as a single unit with an angular velocity of -2.4 rad/s. The axis of rotation for this unit is the same as that for the separate disks. What is the moment of inertia of disk B
Answer:
I = 4.4 kg*m^2
Explanation:
As no external torques are present, total angular momentum must be conserved, as follows:[tex]L_{o} = L_{f} (1)[/tex]
The initial angular momentum of the two disks rotating separately, can be written as follows:[tex]L_{o} =I_{A} * \omega_{oA} + I_{B} * \omega_{oB} (2)[/tex]
Replacing by the givens, we get:[tex]L_{o} = 3.4kg*m2 * 7.2rad/s + I_{B} * (-9.8 rad/s) (3)[/tex]
The final angular momentum Lf, as the axis of rotation remains the same, is the product of the moment of inertia of both disks rotating as one, and the common angular velocity ωf, as follows:[tex]L_{f} = (I_{A} + I_{B}) *\omega_{f} (4)[/tex]
Replacing by the givens, we get:[tex]L_{f} = (3.4 kg*m2 + I_{B} ) * (-2.4 rad/s) (5)[/tex]
From (3) and (5), we can solve for IB, as follows:IB = 4.4 kg*m2Two masses 1.2kg and 1.8kg are connected to the ends of a rod of length 2m. Find the moment of inertia about the axes, 1)going through the mid point of the rod. 2)going through the centre of mass of two masses.
Answers: 1) 3 kg m²
2) 2.88 kg m²
Explanation: Question 1
I = m(r)²+ M(r)²
I = 1.2 kg × (1 m )² +1.8 kg ×(1 m )²
∴ I = 3 kg m²
Question 2
ACCORDING TO THE DIAGRAM DRAWN FOR QUESTION 2
we have to decide where the center of gravity (G) lies and obviously it should lie somewhere near to the greater mass. (which is 1.8 kg). Since we don't know the distance from center of gravity(G) to the mass (1.8 kg) we'll take it as 'x' and solve!!
moments around 'G'
F₁ d ₁ = F₂ d ₂
12 (2-X) = 18 (X)
24 -12 X =18 X
∴ X = 0.8 m
∴ ( 2 - x ) = 1.2 m
∴ Moment of inertia (I) going through the center of mass of two masses,
⇒ I = m (r)² +M (r)²
⇒ I = 1.2 × (1.2)² + 1.8 × (0.8)²
⇒ I = 1.2 × 1.44 + 1.8 × 0.64
⇒ I = 1.728 + 1.152
⇒ ∴ I = 2.88 kg m²
∴ THE QUESTION IS SOLVED !!!
Pelican hunts fish in the water as th pelican the waters surface why must it aim for the fish in a slightly different place than where the fish appears to be located
The Pelican must aim differently than where the fish appears to be because light is refracted from air to water.
Refraction is the change in the direction of a wave at the interface between two media. The effects of refraction are easily seen when light is travelling from air to water hence objects are not really where they appear to be when viewed above the water surface.
Hence, the Pelican must aim differently than where the fish appears to be because light is refracted from air to water.
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Joe applies a force of 50 N to a box which has a mass of 15 kg. What is the acceleration of the box?
a.
Answer:
3.333 m/s^2
Explanation:
50/15 = 3.33 m/s^2
According to The Flash, The heroes top speed is Mach 3.3, or 2,500 miles per hour. How
long would it take for him to run around the planet? (circumference of the earth is
roughly 25,000 miles) *
Answer:
nearly 2 days or less hes fast but not that fast
Explanation:
but maybe he can run it in five minutes
Select the correct answer.
Derick has been working as a first responder since many years. His primary responsibility at a crime scene is to question witnesses and gather
useful information from the scene. Which of these first responder career roles does Derick fit into?
OA paramedic
OB. police officer
Oc. fire truck driver
OD. firefighter
Answer:
Police officer
Explanation:
Because police officers wants to gather information on what happens and question people to know everything. That is what Derick is doing
a machine
of efficiency of 70% is used to raise
a body of
mass 80 kg through
a vertical distance of 3m in
40 seconds. Calculate the power input. (Take g = 10 m/s²)
Answer:
Power_input = 85.71 [W]
Explanation:
To be able to solve this problem we must first find the work done. Work is defined as the product of force by distance.
[tex]W = F*d[/tex]
where:
W = work [J] (units of Joules)
F = force [N] (units of Newton)
d = distance [m]
We need to bear in mind that the force can be calculated by multiplying the mass by the gravity acceleration.
Now replacing:
[tex]W = (80*10)*3\\W = 2400 [J][/tex]
Power is defined as the work done over a certain time. In this way by means of the following formula, we can calculate the required power.
[tex]P=\frac{W}{t}[/tex]
where:
P = power [W] (units of watts)
W = work [J]
t = time = 40 [s]
[tex]P = 2400/40\\P = 60 [W][/tex]
The calculated power is the required power. Now as we have the efficiency of the machine, we can calculate the power that is introduced, to be able to do that work.
[tex]Effic=0.7\\Effic=P_{required}/P_{introduced}\\P_{introduced}=60/0.7\\P_{introduced}=85.71[W][/tex]
A phosphodiester bond is used to:
A. Join glycerol to fatty acids
B. Join two nucleotides into a polynucleotide
C. Join two glucose molecules
D. Join two amino acids into a polypeptide
Answer:
A. Join glycerol to fatty acids
Explanation:
I majored in Physics.
how is red shift evidence of the big bang
it implies our universe is expanding
it implies our universe is collapsing
it implies our universe is standing still
Answer:
it implies our universe is expanding
what is the difference between alcoholic and Mercury thermometer based on their function?
An astronaut floating at rest in space throws a wrench in one direction and subsequently recoils back with a velocity in the opposite direction. Which of the following statements is/are true?
I. The velocity of the wrench is equal and opposite to the velocity of the astronaut.
Il. The momentum of the wrench is equal and opposite to the momentum of the astronaut.
III. The impulse applied to the wrench is equal and opposite to the impulse applied to the astronaut
a) ll and ill only
b) I only II only
c) I, II, and III
d) I and Il only
Answer:
a) ll and Ill only
Explanation:
Let the mass of the wrench = m
and the mass of the astronaut = M
Initially, the velocity of the astronaut and wrench are zero.
The astronaut throws the wrench in one direction and subsequently recoils back with a velocity in the opposite direction.
Let v and V be the velocity of the wrench and the velocity of the astronaut respectively.
In space, there is no external force acting, the momentum must be conserved.
So, m(0)+M(0)=m(v)+M(V)
So, 0=mv+MV
[tex]\Rightarrow mv=-MV[/tex] ...(i)
Here, the momentum of the wrench = mv, and the momentum of the astronaut= MV. The negative sign showing that both the momentum are in opposite direction.
Therefore, the momentum of the wrench is equal and opposite to the momentum of the astronaut.
According to Newton's second law, the rate of change of momentum = applied force.
Let it take [tex]\Delta t[/tex] seconds to change the momentum.
So, for the wrench
[tex]m(v-0)/\Delta t= F_w \\\\\Rightarrow m(v-0)=F_w\Delta t \\\\\Rightarrow mv=F_w\Delta t \cdots(ii)[/tex]
Here, [tex]F_w\Delta t[/tex] is the impulse applied to the wrench.
Similarly, for the astronaut
[tex]M(-V-0)/\Delta t= F_a[/tex] [negative sign (-V) for opposite direction]
[tex]\Rightarrow M(-V-0)=F_a\Delta t \\\\\Rightarrow -MV=F_a\Delta t[/tex]
Here, [tex]F_a\Delta t[/tex] is the impulse applied to the astronaut.
So, the impulse on the astronaut.
By using equations (i) and (ii)
[tex]F_a\Delta t=F_w\Delta t[/tex]
Therefore, the impulse applied to the wrench is equal and opposite to the impulse applied to the astronaut.
Hence, option (a) is correct.
What is unique regarding the abdominal muscle when is compared to other muscle in the body?
(A) it is a very large muscle
(B) it does not develop easily
(C) it can move the body either from the ribcage or the pelvis.
(D) it can get injured easily if you perform a lot os repetitions.
(E) none of the above
How do the potential and kinetic energy change as the sled moves down the slope?
IF YOU DID SLED WARS WORKSHEET HELP ME PLEASE
Answer:
when a sled is moving, the kinetic energy is changing beacuse of the speed and mass. its cause the sled to move, and changes because you aren't at a constant speed. potential energy changes when you get on. because you are adding more weight causing the gravity to change.
Use the image below to answer the question.
What does the arrow 'B' represent?
Question 7 options:
wavelength
refraction
frequency
compression
Do YOU think aliens are real? HELP PLS
Which answer best displays Adam's use of the civic virtue "diversity"?
Diversity means something is benifical to an entire group.
Diversity means fair treatment of all people the
Answer:Yes
Explanation:yeah i think it could be possible because the universe is so far and wide its probably infinite and if we did i personally believe that we would be absolutely be annihilated by them because we would be so far behind technology wise we would have no use for the\
YOU FELL FOR IT FOOL THUNDER CROSS SPLIT ATTACK
what type of plate boundary decreases the amount of the Earth's crust?
Answer:
Convergent.
Explanation:
Just as oceanic crust is formed at mid-ocean ridges, it is destroyed in subduction zones. Subduction is the important geologic process in which a tectonic plate made of dense lithospheric material melts or falls below a plate made of less-dense lithosphere at a convergent plate boundary.
Define specific vision??
Answer:an inspirational statement of an idealistic emotional future
Explanation:
I don't know if it's right tho
Answer:
The document that state tge currentand future objectives of an organization.
If a spaceship traveling 1000 miles per hour enters an area free of gravitational forces, its engine must run at some maximum level in order to maintain the ships velocity.
Question is whether the statement made is true or false.
Answer:
False
Explanation:
The statement is false.
Thus is because even though we are told that the spaceship is running at 1000 miles per hour and an enters an area free of gravitational forces, there is no rule or law that says the engine must run at some maximum level to maintain the velocity.
So, that's why it is false as there is no proof of the statement from every law of physics.
Suppose that the separation between two speakers A and B is 6.60 m and the speakers are vibrating in-phase. They are playing identical 126-Hz tones and the speed of sound is 343 m/s. An observer is seated at a position directly facing speaker B in such a way that his line of sight extending to B is perpendicular to the imaginary line between A and B. What is the largest possible distance between speaker B and the observer, such that he observes destructive interference
Complete question
The diagram for this question is shown on the first uploaded image
Answer:
The largest possible distance is [tex]e = 15.33 \ m[/tex]
Explanation:
From the question we are told that
The separation between Speaker at position A and B is AB = 6.60 m
The frequency of the tune which the speaker are playing is [tex]f = 126 \ Hz[/tex]
The speed of sound is [tex]v = 343 \ m/s[/tex]
Generally the wavelength of the tune playing is mathematically represented as
[tex]\lambda = \frac{v}{f}[/tex]
=> [tex]\lambda = \frac{343}{ 126}[/tex]
=> [tex]\lambda = 2.72 \ m[/tex]
Let the observer be at position D
Generally the distance A and is mathematically evaluated using Pythagoras theorem as
[tex]AC = \sqrt{AB ^2 + BC^2}[/tex]
Let BC = e
So
[tex]AC = \sqrt{6.60 ^2 + e^2}[/tex]
Generally the path difference between the first and the second speaker from the observer point of view is mathematically represented as
[tex]P = AC - BC[/tex]
=> [tex]P = \sqrt{6.60 ^2 + e^2} - e[/tex]
Generally the condition for destructive interference is mathematically represented as
[tex]P = (2n - 1 )\frac{\lambda}{2}[/tex]
Here n is the order of the fringe which is one
=> [tex]\sqrt{6.60 ^2 + e^2} - e = (2 * 1 - 1 )\frac{2.72}{2}[/tex]
=> [tex]\sqrt{6.60 ^2 + e^2} - e = 1.36[/tex]
=> [tex]6.60 ^2 + e^2 =( 1.36 +e)^2[/tex]
=> [tex]6.60 ^2 + e^2 =1.8496 + 2.72e +e^2[/tex]
=> [tex]e = 15.33 \ m[/tex]