Answer:
c. -288 J
Explanation:
Given;
mass of the block, m = 4 kg
velocity of the block, v = 12 m/s
deceleration of the block, a = 3 m/s²
Apply work-energy theorem;
work done in stopping the block = kinetic energy of the block
W = ¹/₂mv²
where;
W is the magnitude of the work done by the force
W = ¹/₂ x 4 x 12²
W = 288 J
Since the work done by the force is in opposite direction, then the value of the work done by the force is -288 J
A uniform rod of length 80cm rotated in the xy plane about a frictionless pin passing through one end (as shown in figure). If the angular
velocity of the rod is 4rad/s, find the linear velocity (in m/s) of its mid-point C
Rod
Pin
С
Select one:
O a. 0.5
O b. 1.6
O c. 1.3
O d. 0.8
Answer:
Linear velocity (in m/s) = 1.6 m/s
Explanation:
Given:
Length of rotational plane = 80 cm
Angular velocity of the rod = 4rad/s
Find:
Linear velocity (in m/s)
Computation:
Radius from mid point C = Length of rotational plane / 2
Radius from mid point C = 80 / 2
Radius from mid point C = 40 cm
Radius from mid point C = 0.4 m
Linear velocity (in m/s) = Angular velocity of the rod x Radius from mid point C
Linear velocity (in m/s) = 0.4 x 4
Linear velocity (in m/s) = 1.6 m/s
a particle covers 10m distance in 2sec. if final velocity is 8m/s, find initial velocity
Answer:
vi =2
Explanation:
Δx = 1/2 (vi + vf) t
10 = 1/2 ( vi + 8 ) 2
10 = vi + 8
10-8 = vi
vi = 2 m/s
vi= initial velocity
vf= final velocity
Δx= distance
t= time
The instrument measuring the temperature change between inspired cool air and expired warm air is called?
Answer:
It's called a Spirometer
A solid, uniform sphere of mass 2.0 kg and radius 1.8 m rolls from rest without slipping down an inclined plane of height 7.5 m. What is the angular velocity of the sphere at the bottom of the inclined plane
Answer:
[tex]w^2=5.5rads/s[/tex]
Explanation:
From the question we are told that:
Mass [tex]m=2.0kg[/tex]
Radius [tex]r=1.8m[/tex]
Height [tex]h=7.5m[/tex]
Generally the equation for Potential energy is mathematically given by
Potential energy=Kinetic energy+Rotational energy
[tex]mgh=\frac{1}{2}mv^2+\frac{1}{2}Iw^2[/tex]
Since there is no slipping
[tex]v=rw[/tex]
Therefore
[tex]mgh=\frac{1}{2}mr^2w^2+\frac{1}{2}Iw^2[/tex]
Where
[tex]I=\frac{1}{2}mr^2[/tex]
[tex]l=3.24m[/tex]
[tex]2*9.81*7.5=\frac{1}{2}(2)(1.8)^2w^2+\frac{1}{2}(3.24)w^2\\\\[/tex]
[tex]147.15=3.24w^2+1.62w^2[/tex]
[tex]w^2=\frac{147.15}{4.86}[/tex]
[tex]w^2=\sqrt{\frac{147.15}{4.86}}[/tex]
[tex]w^2=5.5rads/s[/tex]
If you cut a permanent magnet into four pieces,
you will have what?
A) four temporary magnets
B) four smaller permanent magnets
C) two north poles and two south poles
D)four objects that are no longer magnets
you would have C) two north poles and two south poles
a 4 kg block is moving at 12 m/s on a horizontal frictionless surface. a constant force is applied such that the block slows with an acceleration of 3 m/s^2. how much work must this force do to stop the block?
a. -576 J
b. -360 J
c. -288 J
d. 360 J
e. 576 J
walk me through this please. NO LINKS.
Answer:
Is there a picture?
Explanation:
An object has one force acting on it. It is a 33- Newton force pointing downward. To create a net force of zero on the object, which force must be applied to it?
As soon as I see "Which...", I know that the last part of the question is the list of answer choices, but you decided not to let us see them.
The answer is: A 33-Newton force pointing upward.
What is the term for the force that holds protons and neutrons together in the nucleus of
an atom?
a electromagnetism
b. gravity
c. the strong force
d the weak force
Which of these devices is a type of aerobic exercise machine?
Answer:
Aerobic exercise is an important component of a healthy lifestyle. Find out more about aerobic equipment that can help keep you fit.
Aerobic equipment simulates the movements of aerobic exercises such as walking, jogging, rowing, skiing, hiking, biking, and climbing. These activities rhythmically and continuously move your large muscles — the key to getting your heart beating fast enough and long enough for aerobic conditioning.
Phase portraits (or phase diagrams) provide a powerful tool to visualize the dynamics of ODE systems.
a. True
b. False
Select the correct answer from each drop-down menu.
After World War II, political leaders from various countries discussed ways to strengthen individual-as well as
economies. They began promoting
to boost production and exports,
Answer: I think it’s Global for the 1st one
And free trade for the 2nd one
Explanation:
The correct answer is: "After World War II, political leaders from various countries discussed ways to strengthen individual economies." They began promoting economic policies to boost production and exports.
What happened after World War II?After World War II, many countries were left with weakened economies and infrastructure, and there was a need for economic recovery and growth. To achieve this, political leaders from different countries came together to discuss ways to strengthen their individual economies and also promote international economic cooperation. One of the ways they did this was by promoting economic policies that aimed to boost production and exports. This involved policies that encouraged businesses to increase their output and create more jobs, as well as policies that made it easier for countries to trade with each other.
Hence, after World War II, political leaders from various countries discussed ways to strengthen their individual economies. They began promoting economic policies to boost production and exports.
Learn more about World War II's aftermath here.
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If the height is 10m, what is the potential energy? Asuming that the mass is 10
[tex]\huge{\textit{\sf{{\color{m}{Answer}}{\color{b}{࿐}}}}}[/tex]
we know,
[tex] \boxed{potential \: energy = mgh}[/tex]
So,
[tex]\longmapsto10 \times 9.8 \times 10[/tex]
[tex]\longmapsto980 \: joules[/tex]
The planets and the asteroid belt orbit the Sun in __________. Multiple Choice a spherical distribution, whereas the Oort cloud of comets orbits in a plane planes, whereas the Oort cloud of comets has a spherical distribution orbits nearly identical to the Oort cloud of comets planes tilted at an angle to the plane of the Oort cloud of comets a spherical distribution similar to that of the Oort cloud of comets
Answer:
planes, whereas the Oort cloud of comets has a spherical distribution.
Explanation:
A planet can be defined as a large celestial body having sufficient mass to allow for self-gravity and make it assume a nearly circular shape (hydrostatic equilibrium), revolves in an orbit around the Sun in the solar system and has a cleared neighborhood.
Basically, the planets are divided into two (2) main categories and these includes;
I. Outer planets: these planets are beyond the asteroid belt and comprises of jupiter, saturn, uranus and neptune, from left to right of the solar system.
II. Inner planets: these planets are the closest to the sun and comprises of mercury, venus, earth and mars.
These outer planets are made mostly of gases (hydrogen and helium) causing them to be less dense than the solid inner planets. These gases are generally known to be less dense in terms of physical properties.
Oort cloud is also referred to as Opik and it typically comprises of icy pieces of planetesimals (space debris) that spherically surrounds the sun at distances ranging from about 3000 to 100,000 AU.
Hence, the planets and the asteroid belt orbit the Sun in planes, whereas the Oort cloud of comets has a spherical distribution.
You have two electrical devices plugged into the same socket in parallel and draws 120 V. The first device has a resistance of 20 Ω the other device has a resistance of 10 Ω.
What is the total resistance?
The devices don't "draw" 120v. The 120v comes to your house from the power company. They decide it should be 120v and that's what they send you. It's hypothetically technically possible for you to change that, but if you try it, you'll definitely burn the house down.
The total resistance of those two devices in parallel is 6 and 2/3 ohms. That doesn't depend on what they're plugged into. It would still be 6 and 2/3 ohms if they were connected in parallel, wrapped in tissue, sealed in a jar of chicken soup and stored in a box on a high shelf.
But since they ARE plugged into 120v, they draw 18 Amperes from the socket, and they turn all of that electrical energy into 2160 watts of heat. That's about the same as a good size toaster oven, and you have to figure out a way to get rid of all that heat before you burn the house down.
In an electric resistance of 20 ohms, if the current intensity passing through it
is doubled, its value becomes ........ ohms.
b. 20
d. 40
a. 10
c. 30
Answer:
a. 10 ohms.
Explanation:
Given;
first electrical resistance, r₁ = 20 ohms
let the first current through the circuit = I₁
let the second current through the circuit, I₂ = 2I₁ (since it is doubled)
then, the new value of the resistance after doubling the current = r₂
the current intensity is given as;
[tex]\frac{dI}{dt} = I = \frac{v}{r} \\\\I_1r_1 = I_2r_2\\\\r_2 = \frac{I_1r_1}{I_2} \\\\r_2 = \frac{I_1 \times 20}{2I_1 } \\\\r_2 = 10 \ ohms[/tex]
Therefore, the new value of the resistance is 10 ohms.
What is the frequency of microwaves of wavelength 3 cm?
Give your answer to the
nearest GHz and without units.
Answer:
10 GHz
Explanation:
Applying,
v = λf.................... Equation 1
Where v = speed of microwave, λ = wavelength, f = frequency.
make f the subject of the equation
f = v/λ................ Equation 2
Note: Microwave is an electromagnetic wave, and all electromagnetic wave have the same speed, which is 3×10⁸ m/s
From the question,
Given: λ = 3 cm = 0.03 m
Constant; v = 3×10⁸ m/s
Substitute these values into equation 2
f = 3×10⁸/(0.03)
f = 10¹⁰ Hz
f = (10¹⁰/10⁹) GHz
f = 10 GHz
You drop a 10 kg bowling ball off a 2 story building, what is the force generated by
the bowling ball when it hits the ground
Answer:i
Explanation:
which choice displays the effects of quantum mechanics? check all that apply
atoms
subatomic particles
particles that are 10^-9m
microtechnology systems
protons
neutrons
particles that are 10^-3m
Answer:
A,B,C,D,F,G
Explanation:
Edge 2021
The atoms, subatomic particles, particles that are 10^-9m, microtechnology systems, neutrons and particles that are 10^-3m will displays the effects of quantum mechanics.
What is Quantum Mechanics?Quantum Mechanics is the branch of mechanics deals with the mathematical description of the motion and interaction of subatomic particles, incorporating the concepts of quantization of energy, wave–particle duality, the uncertainty principle, and the correspondence principle is Quantum Mechanics.
It is theory says at subatomic level, energy exists in discrete levels as "quanta" and particles behave as waves.
A Subatomic particles are the particle that are present inside an atom. These particles are electrons, protons, and neutrons.
Thus, atoms, subatomic particles, particles that are 10^-9m, microtechnology systems, neutrons and particles that are 10^-3m will displays the effects of quantum mechanics.
Learn more about Quantum Mechanics;
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Un corredor hace los 400 metros lisos en 50 seg. Calcula la velocidad en la carrera.
Answer:
8 meters/second
Explanation:
Rate x Time = Distance
R x T = D
R x 50sec = 400meters
R x 50sec/50sec = 400meters/50sec
R = 8meters/sec
An object
moves through space with balanced forces acting on it. Which statement
best describes the speed and direction of the object as long as the forces acting on it
remain balanced?
Pls answer number 4 and an explanation
Answer: G the speed and direction of the object will remain constant.
Does the law of attraction actually have a basis in physics?
Answer:
Scientific theories are cited by proponents of the Law of Attraction as evidence in its favor. It, on the other hand, has no theoretical basis. A variety of scientists have questioned the promoters' abuse of scientific principles.
An 80 kg astronaut has gone outside his space capsule to do some repair work. Unfortunately, he forgot to lock his safety tether in place, and he has drifted 5.0 m away from the capsule. Fortunately, he has a 1000 W portable laser with fresh batteries that will operate it for 1.0 h. His only chance is to accelerate himself toward the space capsule by firing the laser in the opposite direction. He has a 10-h supply of oxygen. His only chance is to accelerate himself toward the space capsule by firing the laser in the opposite direction. He has a 10-h supply of oxygen.
Required:
How long will it take him to reach safety?
Answer:
t = 3.924 s
Explanation:
First, we will calculate the amount of work required to get the astronaut back to the capsule:
[tex]W = Fd\\[/tex]
where,
W = work required = ?
F = Force = Weight = mg = (80 kg)(9.81\ m/s²) = 784.8 N
d = distance = 5 m
Therefore,
[tex]W = (784.8\ N)(5\ m)\\W = 3924 J[/tex]
Now the time can be calculated as:
[tex]Power = \frac{W}{t}\\t = \frac{W}{Power}\\\\t = \frac{3924\ J}{1000\ W}\\\\[/tex]
t = 3.924 s
A gondola can carry 20 skiers, with a total mass of up to 2250 kg. The gondola ascends at a constant speed from the base of a mountain, at 2150 m, to the summit at 3345 m. (a) How much work does the motor do in moving a full gondola up the mountain
Answer:
[tex]$2.63\times 10^{7} \ J$[/tex]
Explanation:
Given :
Total mass that a gondola can carry, m = 2250 kg
Displacement, s = 3345 - 2150
= 1195 m
Gravitational force, F = mg
= 2250 x 9.8
= 22050 N
Therefore the work done by the motor in moving the full gondola up the mountain,
W = F x s
= 22050 x 1195
= [tex]$2.63\times 10^{7}$[/tex] J
Definition of waves
Answer:
A wave can be described as a disturbance that travels through a medium from one location to another location.
Explanation:
DESCRIBE THE REQUIREMENTS OF AN INTERNET CONNECTION?
please tell me the answer
Answer: The basic requirements for connecting to the Internet are a computer device, a working Internet line, and the right modem for that Internet line. In addition, software programs such as Internet browsers, email clients, Usenet clients, and other special applications are needed in order to access the Internet.
Explanation: brainleist pls :)
If I have a sphere rolling on a table with an initial velocity and then it falls off the edge of the table, from this point on it is taken as if my initial velocity were zero, or it starts from the initial velocity that I had before in the table?
Answer:
The initial velocity after leaving the table is the same as it was before leaving the table (nothing is present to produce discontinuties in the velocity).
Before leaving the table the vertical velocity was zero and is zero when it leaves the table.
The horizontal velocity is constant with no forces present to change the velocity.
A sample contains radioactive atoms of two types, A and B. Initially there are five times as many A atoms as there are B atoms. Two hours later, the numbers of the two atoms are equal. The half-life of A is 0.77 hours. What is the half-life of B in hours?
Answer:
Explanation:
Initially no of atoms of A = N₀(A)
Initially no of atoms of B = N₀(B)
5 X N₀(A) = N₀(B)
N = N₀ [tex]e^{-\lambda t}[/tex]
N is no of atoms after time t , λ is decay constant and t is time .
For A
N(A) = N(A)₀ [tex]e^{-\lambda_1 t}[/tex]
For B
N(B) = N(B)₀ [tex]e^{-\lambda_2 t}[/tex]
N(A) = N(B) , for t = 2 h
N(A)₀ [tex]e^{-\lambda_1 t}[/tex] = N(B)₀ [tex]e^{-\lambda_2 t}[/tex]
N(A)₀ [tex]e^{-\lambda_1 t}[/tex] = 5 x N₀(A) [tex]e^{-\lambda_2 t}[/tex]
[tex]e^{-\lambda_1 t}[/tex] = 5 [tex]e^{-\lambda_2 t}[/tex]
[tex]e^{\lambda_2 t}[/tex] = 5 [tex]e^{\lambda_1 t}[/tex]
half life = .693 / λ
For A
.77 = .693 / λ₁
λ₁ = .9 h⁻¹
[tex]e^{\lambda_2 t}[/tex] = 5 [tex]e^{\lambda_1 t}[/tex]
Putting t = 2 h , λ₁ = .9 h⁻¹
[tex]e^{\lambda_2\times 2}[/tex] = 5 [tex]e^{.9\times 2}[/tex]
[tex]e^{\lambda_2\times 2}[/tex] = 30.25
2 x λ₂ = 3.41
λ₂ = 1.7047
Half life of B = .693 / 1.7047
= .4065 hours .
= .41 hours .
A system is in liquid-vapor mixture of 0.5 kg of saturated water vapor and 0.5 kg
of saturated liquid. Calculate the quality.
Answer:
x = 0.5 = 50%
Explanation:
The quality of a water liquid-vapor mixture can be defined as the fraction of water vapor present in the water liquid-vapor mixture. Therefore, it can be calculated by the use of the following formula:
[tex]x = \frac{m_{vap}}{m}[/tex]
where,
x = quality = ?
m_vap = mass of saturated water vapor = 0.5 kg
m = total mass = mass of saturated vapor + mass of saturated liquid
m = 0.5 kg + 0.5 kg = 1 kg
Therefore,
[tex]x = \frac{0.5\ kg}{1\ kg}[/tex]
x = 0.5 = 50%
Question 3 of 5 What happens to the particles in a substance as it melts? O A. The particles slow down and become fixed in place. B. The particles move more quickly but stay fixed in place. O C. The particles slow down and move closer together, but they can still move around. O D. The particles move more quickly and begin to move from place to place. SUBMIT
Answer:
D. The particles move more quickly and begin to move from place to place.
Explanation:
If 03.4 kg of water at 69°C is changed into steam at 100°C, how will the energy be used? specific heat capacity of water is 4200J/kg C and latent heat is 2,260 000J/Kg.
A. 7864513 J
B. 8126680 J
C. 329758 J
D. 742976 J
With explanation please
Answer:
The answer is B.
Explanation:
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