Answer:
[tex]\huge\boxed{\sf Work\ done = 4 kJ}[/tex]
Explanation:
Since work done is in the form of potential energy, we will use the formula of potential energy here.
We know that,
P.E. = mghWhere,
m = mass = 20 kg
g = acceleration due to gravity = 10 m/s²
h = vertical height = 20 m
So,
Work done = mghWork done = (20)(10)(20)
Work done = 4000 joules
Work done = 4 kJ
[tex]\rule[225]{225}{2}[/tex]
Which of the following is a good radiator of heat option is (a) a shiny silvered surface option (b) a dull black surface option (c) a white surface option (d) a green coloured surface
Answer:
option b
Step by step explanation:
a dull black surface is a good radiator of heat
Answer:
option b is the answer
A cylinder 15.0 cm in diameter rotates at 1000 rpm. (a) what is its angular velocity in rad/s? (b) what is the tangential velocity of a point on the rim of the cylinder?
Answer:
(a) Approximately [tex]105\; {\rm rad \cdot s^{-1}}[/tex].
(b) Approximately [tex]15.7\; {\rm m \cdot s^{-1}}[/tex], assuming that this cylinder is rotating along the axis that goes through the center.
Explanation:
The unit [tex]{\rm rpm}[/tex] stands for "revolutions per minute", where each revolution is [tex]2\, \pi[/tex] radians.
With an angular velocity of [tex]1000\; {\rm rpm}[/tex], this cylinder would turn [tex]1000\times 2\, \pi = 2000\, \pi[/tex] radians every minute ([tex]60\; {\rm s}[/tex]). Thus, the angular velocity of this cylinder would be:
[tex]\begin{aligned} \omega &= \frac{2000\, \pi\; {\rm rad}}{60\; {\rm s}} \\ &\approx 104.720\; {\rm rad \cdot s^{-1}}\end{aligned}[/tex].
A point at the rim of this cylinder would be at a distance of [tex]r = 15.0\; {\rm cm} = 0.150\; {\rm m}[/tex] from the axis of revolution of this cylinder. If the angular velocity of this cylinder is [tex]\omega[/tex], the tangential velocity of this point would be:
[tex]\begin{aligned} v&= \omega\, r \\ &= \frac{2000\, \pi}{60\; {\rm s}} \times 0.150\; {\rm m} \\ &\approx 15.7 \; {\rm m\cdot s^{-1}}\end{aligned}[/tex].
Help meeee is for tomorrow, plssss!!!
2) For the association of resistors below:
a) The equivalent resistor between A and B.
b) The total electric current that runs through the circuit, knowing that the electrical voltage between terminals A and B is valid 21 V(volts).
c) The value of the electric current passing through the resistor of 1.0 Ohm.
d) The power dissipated through the 8.0 Ohm resistor.
(a) The equivalent resistance of the circuit is 0.52 ohms.
(b) The total electric current that runs through the circuit is 40.38 A.
(c) The value of the electric current passing through the resistor of 1.0 Ohm is 21 A.
(d) The power dissipated through the 8.0 Ohm resistor is 55.13 W.
Equivalent resistance of the circuitThe equivalent resistance of the circuit is calculated as follows;
1/R = 1/(1 + 1) + 1/(2 + 2 + 2) + 1/(6) + 1/(2) + 1/8 + 1/8 + 1/6 + 1/6
1/R = 1/2 + 1/6 + 1/6 + 1/2 + 1/8 + 1/8 + 1/6 + 1/6
1/R = 1 + 2/3 + 1/4
1/R = 23/12
R = 12/23
R = 0.52 ohms
Total current through the circuitV = IR
I = V/R
I = 21/0.52
I = 40.38 A
Current through 1 ohm resistorV = IR
I = V/R
I = 21/1
I = 21 A
Power dissipated through 8 ohm resistorP = V²/R
P = (21)²/8
P = 55.13 W
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At 6: 00 am, a motorbike set off from town A to town B at a speed of 40km/h. At the same time, a car set off from town B to town A at a speed of 60km/h. What time did they meet
Answer:
One would need to know how far apart the towns are:
T = SA / 40 time it takes for first cyclist to travel S1
T = SB / 60 time it takes for cyclist B to travel distance S2
SA + SB = S the distance between the towns
SB = 60 / 40 SA = 1.5 SA
SA + 1.5 SA = S
S = 2.5 SA where cyclist travels distance SA
The time will depend on the separation of the towns.
The prop blades of an airplane spin with a linear velocity of 875 m/s and have a centripetal acceleration on the farthest edge of 180,000 m/s^2 the radius of the prop blades?
The radius of the prop blade of an airplane is determined as 4.25 m.
Radius of the prop blade
The radius of the prop blade of an airplane is calculated as follows;
a = v²/r
where;
v is the linear speedr is the radius of the prop bladea is the centripetal accelerationr = v²/a
r = (875²)/(180,000)
r = 4.25 m
Thus, the radius of the prop blade of an airplane is determined as 4.25 m.
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10. In Freudian theory, which one of the following is an example of a Thanatos instinct, which includes aggression, trauma, and risky behaviors?
A. going to school.
B. seeking nourishment.
C. joining a basketball club.
D. substance abuse.
In Freudian theory, substance abuse is one of the following an example of a Thanatos instinct, It includes aggression, trauma, and risky behaviors, Therefore the correct answer is option D
What is the Freudian theory?The psychoanalytic approach to adult personality development is built on the theories of Sigmund Freud. His beliefs addressed four topics: level of consciousness, personality structure, and stages of psychosexual development. These personality qualities interact to create anxiety, which needs to be controlled via a range of defense mechanisms. These strategies mask the true, anxiety-related causes of one's conduct.
Freud's theories also have limited applicability to the fields of gerontology and geriatric medicine because they postulate that personality development related to his stages of psychosexual development essentially ends in adolescence.
Thus, Substance abuse is one of the Thanatos instincts, which also include aggression, trauma, and risky behavior, according to Freudian theory. Option D is the correct answer.
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Explain how horizontal motion can be uniform while vertical motion is accelerated.
How will projectile motion be affected when drag due to air resistance is taken into
consideration?
What is the energy of the photon emitted when an electron in a mercury atom drops from energy level f to energy level b?
1.
8.42 ev
2.
5.74 ev
3
3.06 ev
4.
2.68 ev
The energy of the photon emitted when an electron in a mercury atom drops from energy level f to energy level b is 3.06 eV.
Change in energy level of the electronWhen photons jump from a higher energy level to a lower level, they emit or radiate energy.
The change in energy level of the electrons is calculated as follows;
ΔE = Eb - Ef
ΔE = -2.68 eV - (-5.74 eV)
ΔE = 3.06 eV
Thus, the energy of the photon emitted when an electron in a mercury atom drops from energy level f to energy level b is 3.06 eV.
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Transverse waves are to radio waves as longitudinal waves are to:
1. light waves
2. microwaves
3. ultraviolet waves
4. sound waves
URGENT!!!!
A 500 N weight is hung at the middle of a rope attached to two buildings at the same level. If the breaks in the tension exceed 1800 N, what is the minimum angle the rope can make with the horizontal?
Not sure what you mean by "breaks in the tension" but I suspect you mean the rope will come apart if the tension in the rope exceeds 1800 N.
In the free body diagram for the 500 N weight, we have a figure Y with the net force equations
• horizontal net force:
∑ F[hor] = T₁ cos(θ) - T₂ cos(θ) = 0
• vertical net force:
∑ F[ver] = T₁ sin(θ) + T₂ sin(θ) - 500 N = 0
From the first equation, it follows that T₁ = T₂, so I'll denote their magnitude by T alone. From the second equation, we have
2 T sin(θ) = 500 N
and if the maximum permissible tension is T = 1800 N, it follows that
sin(θ) = (500 N) / (3600 N) ⇒ θ = arcsin(5/36) ≈ 7.9°
is the smallest angle the rope can make with the horizontal.
A scientist tested wellwarm to see how well it insulated a beaker of hot water. she tested wellwarm and three other materials. what was the dependant variable that the scientist measured during the investigation?
Answer:
the dependent variable is the material
Explanation:
because we change the material each time to test which is the best insulator.
this came up in my test today, so i can assure you it is correct!
The centers of two 350 kg spheres are separated by 2.00 m. what is the gravitational force between them?
A child jumps from a moving sled with a speed of 2.2 m/s and in the
direction opposite the sled's motion. The sled continues to move in the forward direction, but with a new speed of 5.5 m/s. If the child has a mass of 38 kg and the sled has a mass 68 kg, what is the initial velocity of the sled?
The initial velocity of the sled will be 7.34 m/sec. V is the initial velocity of the sled.
What is the law of conservation of momentum?According to the law of conservation of momentum, the momentum of the body before the collision is always equal to the momentum of the body after the collision.
The given data in the problem is;
(m₁) mass of child = 38 kg
(u₁) is the initial velocity child = 2.2 m/s
(m₂) is the mass of sled = 68 kg
(u₂) is the initial velocity of sled = ?
(v) is the velocity after collision = 5.5 m/s
According to the law of conservation of momentum;
Momentum before collision =Momentum after collision
[tex]\rm m_1u_1 + m_2u_2 = v(m_1 + m_2)\\\\(38 \times 2.2) + (68 \times V) = 5.5 \times (38+68) \\\\ 83.6 + 68V = 5.5 \times 106 \\\\ 83.6 + 68V =583 \\\\ \rm 68\ V= 583 -83.6 \\\\ \rm 68 \ V= 499.4\\\\ V= 7.34 \ m/sec[/tex]
Hence,the initial velocity of the sled will be 7.34 m/sec.
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A 20.00 kg lead sphere is hanging from a hook by a thin, massless wire 2.80 m long and is free to swing in a complete circle. Treat the sphere as a point mass. Suddenly it is struck horizontally by a 5.00 kg steel dart that embeds itself in the lead sphere. What must be the minimum initial speed of the dart so that the combination makes a complete circular loop after the collision
The minimum initial speed of the dart so that the combination makes a complete circular loop after the collision is 58.5 m/s.
Minimum speed for the object not fall out of the circle
The minimum speed if given by tension in the wire;
T + mg = ma
T + mg = m(v²)/R
tension must be zero for the object not fall
0 + mg = mv²/R
v = √(Rg)
Final speed of the two mass after collisionUse the principle of conservation of energy
K.Ef = K.Ei + P.E
¹/₂mvf² = ¹/₂mv² + mg(2R)
¹/₂vf² = ¹/₂v² + g(2R)
¹/₂vf² = ¹/₂(Rg) + g(2R)
vf² = Rg + 4Rg
vf² = 5Rg
vf = √(5Rg)
vf = √(5 x 2.8 x 9.8)
vf = 11.7 m/s
Initial speed of the dartApply principle of conservation of linear momentum for inelastic collision;
5v = vf(20 + 5)
5v = 11.7(25)
5v = 292.5
v = 58.5 m/s
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what are the similarities and differences between how living and non-living things fly.
Flying animals utilize their wings to create both lift and propulsion by moving them in relation to the body.
What are living and nonliving things?They both consist of fundamentally simple building blocks. They are composed of substance or mass. Atmospheric and molecular building blocks make up the world.
The differences between how living and non-living things fly;
1. Moving both living and non-living objects consumes energy. Flying animals utilize their wings to create both lift and propulsion by moving them in relation to the body.
In contrast to most air vehicles where the components that generate lift wings and thrust engines or propellers are distinct and the wings stay stationary.
Animal aviators like birds as well as natural parachuters like patagial as well as human inventions like aircraft as well as rockets that can power spacecraft and spaceplanes are just a few examples of the many things that can fly.
Hence there are similarities and differences between how living and non-living things fly.
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During the course of a concert, the temperature of a pipe organ gradually increases. As a result, the frequency of the sound from each pipe will ______ throughout the concert.
What happens to the cost of goods when inflation increases?
OA. The cost of goods decreases.
B. The cost of goods increases.
OC. The cost of goods stays the same.
OD. The cost of goods varies.
Answer:
The answer is B
Explanation:
Generally speaking, a company selling goods during periods of inflation will see an increase in its cost of goods sold.When inflation increases, the cost of goods increases. The correct option is B.
Generally speaking, inflation raises the price of products sold. The price of producing and purchasing those things rises together with the prices of goods and services owing to inflation.
This can be attributable to elements like escalating manufacturing costs, rising input costs, and shifting dynamics of supply and demand.
As a result, companies might need to modify their pricing plans to take inflation-related cost increases into account, the cost of goods typically increases when inflation occurs.
Thus, the correct option is B.
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A rock is dropped from a garage roof from rest. the roof is 6.0 m from the ground. determine the velocity of the rock as it hits the ground.
From rest, a rock is dropped from a garage roof. The roof is 6.0 meters above ground level. The rock will reach the earth at a speed of 10.849 meters per second.
What is velocity?The change of displacement with respect to time is defined as the velocity. Velocity is a vector quantity.
it is a time-based component. Velocity at any angle is resolved to get its component of x and y-direction.
Given data:
V(Final velocity)=? (m/sec)
h(height)= 6.0 m
u(Initial velocity)=0 m/sec
g(gravitational acceleration)=9.81 m/s²
Newton's third equation of motion:
[tex]\rm v_y^2 = u_y^2+ 2gh \\\\\rm v_y^2 = 0+ 2gh\\\\\ v_y= \sqrt{2\times 9.81 \ (m/s^2)\times 6.0 (m)} \\\\ v_y=10.849 \ m/sec[/tex]
Hence, the velocity of the rock as it hits the ground will be 10.849 m/sec.
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The arrows in the diagram show the direction of the magnetic fields of the atoms that make up an object. Which sentence best describes the object? A. The object is made of nonmagnetic material. B. The material of the object can attract a magnet. C. The object is weakly magnetic. OD. The material of the object can be magnetized.
Option D, the sentence that best describes the object is the material of the object can be magnetized.
Atoms of magnetic materialThe direction of the magnetic fields of the atoms that make up an object is always aligned towards the north pole or south of the material.
Objects that are made of unmagnetised materials such iron, cobalt and nickel are attracted to either pole of a magnet, but not repelled.
The diagram given shows unmagnetised material, and hence the material of the object can be magnetized.
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please help with this i am not good with this
Answer:
Ball 3 (tennis ball)
Explanation:
Formula we are using :
acceleration = Force / mass
=============================================================
Ball 1 :
⇒ acceleration = 15 N / 0.5 kg
⇒ acceleration = 30 m/s²
===========================================================
Ball 2 :
⇒ acceleration = 15 N / 4.5 kg
⇒ acceleration = 30/9 m/s²
⇒ acceleration = 10/3 m/s²
⇒ acceleration = 3.33 m/s²
===========================================================
Ball 3 :
⇒ acceleration = 15 N/ 0.05 kg
⇒ acceleration = 300 m/s²
============================================================
On comparing, we see that Ball 3 (tennis ball) has the greatest acceleration.
An electromagnetic wave has a wavelength of 10 nm. Calculate its frequency and identify to which part of the electromagnetic spectrum the wave belongs.
The frequency of an electromagnetic wave with wavelength of 10nm will be 3 × 10∧7 Hz and would belong to the X-ray or ultraviolet part of the electromagnetic spectrum due to its wavelength
What is frequency?
Frequency is defined as the number of oscillations of a wave per unit time and is measured in hertz(Hz).
It is also inversely proportional to the wavelength.
How to calculate the frequency
The frequency of an electromagnetic wave can be calculated using the formula;
frequency = velocity of light divided by the wavelength
f = v ÷ λ
Note that the velocity of light = 3 × 10 ∧8 m/s
Wavelength = 10nm
Frequency, f = 3 × 10∧8 ÷ 10 = 3 × 10∧7 Hz
Hence, the frequency of an electromagnetic wave with wavelength of 10nm will be 3 × 10∧7 Hz and would belong to the X-ray or ultraviolet part of the electromagnetic spectrum due to its wavelength.
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A plastic rod that has been charged negatively touches a neutral metal sphere. What kind of charged particle was transferred between the rod
Answer:
Negative particles will be transferred to the sphere,
Assuming the sphere is not grounded the sphere will be negatively charged when the plastic rod is withdrawn,
(The sphere can be positively charged by grounding the sphere and bringing the rod close to the sphere and then remove the grounding to the sphere)
Care must be taken in noting if and when the sphere is grounded.
Our galaxy, the milky way, contains approximately 4.0x1011 starts with an average mass of 2.0x1030kg each. how far away is the milky way from our nearest neighbor, the andromeda galaxy, if andromeda contains roughly the same number of stars and attracts the milky way with a gravitational force of 2.4x1030n?
By applying the law of universal gravitation, the distance between the milky way and the andromeda galaxy is equal to 4.2 × 10¹¹ meters.
Given the following data:
Mass A, m = 4.0 × 10¹¹ kg.Mass B, M = 2.0 × 10³⁰ kg.Gravitational force, F = 2.4 × 10³⁰ Newton.Scientific data:
Gravitational constant = 6.67 × 10⁻¹¹ m/kg²
How to calculate the distance?In order to determine the distance between the milky way and the andromeda galaxy, we would apply the law of universal gravitation.
According to the law of universal gravitation, the distance between two astronomical bodies can be calculated by using this formula:
[tex]d = \sqrt{\frac{GmM}{F} }[/tex]
Substituting the parameters into the formula, we have;
[tex]d = \sqrt{\frac{6.67 \times 10^{-11} \times 2.0 \times 10^{30} \times 4.0 \times 10^{11}}{2.4 \times 10^{30}} }[/tex]
Distance, d = 4.2 × 10¹¹ meters.
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A chemical reaction is the only way to separate a(n)
Answer:
pure substance
Explanation:
yw
when the formula m*g=F-Fg is used?
The formula (ma = F - Fg) is used to determine the net upward force acting on a body.
What is net upward force acting on a body?The net upward force acting on a body is the resultant or sum of all the upward forces acting on a body at a given time.
ma = F - Fg
where;
F is the applied forceFg is the force of gravityma is the resultant forceThus, the formula (ma = F - Fg) is used to determine the net upward force acting on a body.
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Sean, who has a mass of 65-kg, is out roller blading with friends at a speed of 3 m/s. Not realizing he accidentally let the dog out as he was leaving, Sean finds his 12-kg pup at rest in the middle of the street. Sean gracefully scoops the dog up as he skates down the road and proceeds to carry the pup home. Calculate their final velocity.
Velocity: _ m/s
Answer:
2.53m/s
Explanation:
Initial momentum in a system= Final momentum in a system
65kg*3m/s+12kg*0m/s=(65kg+12kg)*v
195kgm/s=77kg*v
v=2.53m/s
Which energy transformation occurs when an electrolytic cell is in operation.
Answer:
An electrolytic cell converts electrical energy into chemical energy.
Explanation:
Can someone tell me what to tick and why for sentences 3 and 5 please
I will give brainliest to whoever answers correct
Measured in joules - Thermal energy
Measured with a thermometer - Temperature
Does not depend on how much material there is - Thermal energy
Measured in degrees Celsius - Temperature
Increases if you heat something for longer - Thermal energy
Sound travels at a rate of 340 m/s in all directions through air. Matt rings a very loud bell at one location, and Steve hears it some time later at his location 450 meters to the south. How long did it take the sound to travel from the bell to Steve's location?
Answer:
110 m/s
Explanation:
because if you subtract 450 from 340 you get 110
The amount of energy required to raise the temperature of one gram of water by one celsius degree is called a
The amount of energy required to raise the temperature of one gram of water by one celsius degree is called a calorie.
How can you define calorie?
In physics, we can define it as a unit of measurement that defines the amount of energy to raise the temperature of 1 gram of water by 1°C. Each material has its unique calorie, however by definition we use water as it is the lowest of all the elements.
Normally, calorimetry is directly linked with the thermal capacity that an element has to contain heat.
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