Answer: When the worker is on the top rung
Explanation: When the ladder was initially resting on the wall, the torque from the normal reaction on ladder from the horizontal surface is equal to the torque from the vertical surface on ladder.
The weight of the worker produces a torque which is in the direction of the torque from the normal reaction on ladder, produced by the vertical surface. Therefore for the ladder to stay in rotational equilibrium, the torque on ladder from the normal reaction produced by the horizontal surface must increase.
This increase is possible when the worker is on the lower rung, but as the worker goes high, the magnitude of normal reaction from the vertical surface would increase, thereby increasing the risk of slipping of ladder.
A car starts from rest and accelerates along a straight line path in one minute. It finally attains a velocity of 40 meters/second. What is the car's average acceleration?
Answer:
it's A
Explanation:
I JUST A FROM THE TOPIC
A 10 kg cart with a momentum of 10 kg• m/s hits a 20 kg cart at rest. Momentum is calculated by using
the formula p = mv, where m is the mass of an object and vis the velocity of an object.
Change in momentum formula
The change in momentum resulting from an external force is called the impulse (I=mv-mvo) and is related to the force applied through the Impulse-Momentum Theorem: I = F tc = mv - mvo . Here F is the external force applied and tc is the amount of time the force is in contact with the object.
The final velocity ( Vf ) of the cart at rest is : 0.5 m/s
Determine the final velocity of cart at restChange in momentum of the objects = m₁ * ΔV = m₂ * ΔV --- ( 1 )
Given that momentum ( p ) = m * v
where ; m₁ = 10 kg , p = 10 kg.m/s , v = ?
calculate for v
v = p/m = 10 kg.m/s / 10 kg
= 1 m/s
Back to equation ( 1 )
= 10 * ( 1 m/s ) = 20 * ( Vf - )
= 10 = -20 Vf
therefore Vf ( final velocity of cart at rest ) = 10 / 20
= 0.5 m/s
Hence we can conclude that The final velocity ( Vf ) of the cart at rest is : 0.5 m/s
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How can different objects interact when they are not even touching?
Answer: Magnetic and gravitational force
Explanation: When a magnet and an iron nail are kept at a distance,the magnet attracts the nail without touching using magnetic force. In this example, the magnet and the nail are interacting.
The earth pulls the moon towards it and keeps it in orbit without touching it, using gravitational force. In this example,the moon and the earth are interacting.
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When Jane drives to work, she always places her purse on the passenger’s seat. By the time she gets to work, her purse has fallen on the floor in front of the passenger seat. One day, she asks you to explain why this happens in terms of physics. What do you say?
Answer:
the vibrations push the purse up and down very fast and gravity pushes the purse down onto the floor
Explanation: does that help
Answer:
Newton's 1st Law
Explanation:
When Jane is driving her purse is being pushed against the seat so when she stops driving it slides forward because of it's mass. So that is why it ends up on the floor.
What is the net force required to give an automobile with a mass of 1,600 kg an acceleration of 4.5 m/s2
Answer:
Fnet=7200 N
Explanation:
Fnet=mass x acceleration
mass= 1600kg acceleration=4.5m/s^2
Answer:
Net force= 7200 N or 7200 N*m/s^2 (It just depends)
Explanation:
1600 kg x 4.5 m/s^2 = 7200 kg*m/s^2 or 7200 N*m/s^2
Which of the following best describes the circuit shown below?
A. Parallel
B. Open
C. Series
D. Short
Answer:
short circuit
Explanation:
the current will not pass through the lamp, but it will go through the small wire (less resistance than the lamp)
what is one basic need that both monkey and a tree have in common
Answer:
water
Explanation:
both a monkey and a tree need water to survive.
Have a great day
Why does the reading on hydrometer increase towards the bottom?
Answer:
They're calibrated to measure, liquids of greatest density.
Explanation:
Sports managers have the potential to earn more than a million dollars per year.
True
false
Answer:
true
Explanation:
hope this helped!
Answer:
true :)
Explanation:
A plane starting from rest accelerates to 40 m/s in 10 s. How far did the plane travel during this time?
PLEASE ANSWER FAST!! Thankew <3
Answer:
400 meters
Explanation:
using the equation:
speed = distance/timeit would look like this when plugged in: 40=d/10d (distance) is the unknown variable, so you have to solve for thatmultiply both sides by 10 since you want to separate d to solve its number. 10d/10=40 × 10the two tens on the d part of the equation would cancel out, leaving only d. Therefore, d = 400Hopefully this helps.
liquid can flow but solid cannot give reason
Answer:
well..
Explanation:
Liquid can flow but solid cannot because of differences in their properties
property of liquid which lets it flow:
inter-particular space is largeinter-particular attraction is small these properties tend to make the molecules of liquid free to flowproperty of solid which tends to obstruct flow:
inter-particular space is small and so it's compactinter-molecular attraction is strong hence no tendency to flowHope this helps!
A rabbit sees carrot to his right and starts jumping towards it with a velocity of 4.0meter per sec it speeds up to its maximum velocity of 13 meter per sec with a constant acceleration of 2.0 metre per sec square how long does it take for the rabbit to go from 4.0 metre per sec to 13.0 metre per square
Answer:
4.5 sec
Explanation:
Initial velocity u = 4 m/s
Final velocity v = 13 m/s
Acceleratiin a = 2 m/s^2
Using v = u + at
Where t is time
13 = 4 + 2t
13 - 4 = 2t
9 = 2t
t = 9/2 = 4.5 sec
Answer:
4.5 s
Explanation:
The initial velocity (u) = 4 m/s, the final velocity (v) = 13 m/s and the acceleration (a) = 2 m/s²
To calculate the time it takes the rabbit to go from 4.0 m/s to 13.0 m/s, we use the formula:
v = u + at
Substituting values to get:
13 = 4 + 2t
Subtracting 4 from both sides:
13 - 4 = 4 + 2t - 4
9 = 2t
Therefore, 2t = 9
Dividing through by 2
2t / 2 = 9 / 2
t = 4.5 s
Therefore it takes the rabbit 4.5 seconds to go from 4.0 m/s to 13.0 m/s
/3
Mickey He hits the puck
when it has an initial
velocity of 3.5 m/s [East].
The stick touches the puck
for 0.250 seconds and
changes the velocity to
6.75 m/s [East]. What is
the acceleration? show
your work below
Question 2
13
Matt plays badminton. He
serves the birdie with a
velocity of 4.25 m/s [right]
covering a displacement of
5.2 m [forward]. How much
time does this birdie's trip
take? show your work
below
Answer:
130m/s^2 and 1.22s
Explanation:
From V = u+at
Where V, u, a, and t are the final velocity, initial velocity, acceleration and time respectively.
v = 6.75m/s
u = 3.5m/s
t = 0.250secs
a = ?
V = u+at
6.75= 3.5+a(0.250)
6.75-3.5 = 0.250a
3.25=0.250a
Divide both sides by 0.250
3.25/0.250= 0.250a/0.250
a = 130m/s^2
The acceleration of the will be 130 meter per second
Question 2
Speed = distance/time
Given that speed= 4.25m/s
Distance = 5.2m and time = ?
4.25m/s = 5.2m/t
Cross multiply
4.25×t = 5.2
Make t the subject by dividing both sides by 4.25
4.25t/4.25 = 5.2/4.25
t = 1.22s
Hence the time taken will be 1.22 seconds
you walk 5 km east then turned and walked 2km west what would your displacement be
Answer:
3km? im a beginner
what are the benefits of physical exercises?
Answer:
Manage your weight
Have lower blood pressure
Lower your risk of falls
it reduces your risk of heart attack
Which kind of investigations allow for the control of variables
Answer:
An experimental investigation allows you to control the variables.
please help..!
How many photons does it emit in 1 sec. Lamp with a power of 90 W, if it emits monochromatic light with
wavelength 600 nm?
Answer:
idk ha ha ha
Explanation:
Oque ocorre com a velocidade se diminuímos o tempo, mantendo a distância constante? E se aumentarmos o tempo? Que tipo de grandeza sao tempo e velocidade?
In what ways are electromagnetic waves differed from mechanical waves?
A. Electromagnetic waves can only travel through matter.
B. Electromagnetic waves transfer matter through empty space.
C. Electromagnetic waves are longitudinal waves
D. Electromagnetic waves can travel through empty space
Answer:
D. Electromagnetic waves can travel through empty space
Explanation:
After a few Google searches, this answer seems the most correct
Electromagnetic waves differ from mechanical waves by the fact that electromagnetic waves can travel through empty space.
What are electromagnetic waves?The electromagnetic radiation consists of waves made up of electromagnetic field which are capable of propogating through space and carry the radiant electromagnetic energy.
The radiation are composed of electromagnetic waves which are synchronized oscillations of electric and magnetic fields . They are created due to change which is periodic in electric as well as magnetic fields.
In vacuum ,all the electromagnetic waves travel at the same speed that is with the speed of air.The position of an electromagnetic wave in an electromagnetic spectrum is characterized by it's frequency or wavelength.They are emitted by electrically charged particles which undergo acceleration and subsequently interact with other charged particles.
Learn more about electromagnetic waves,here:
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State two units bigger than kilogram and how are they related to kilogram
Answer:
quintal and metric tone.
Explanation:
1 quintal= 100kg
1 metric =1000kg
quintal measures mass of cars, trucks etc, but metric measures bigger things like cargo ships
hope it helps
12. In the last three months mr sharma lost 11\2 kg gained 9\4 kg and then lost 15\4 kg. if he now weigh 95 kg, how much did me sharma weigh to begin with ?
(a)100 kg (b)102kg
(c) 106.5. (d) 104kg
Answer:
(b) 102 kg
Explanation:
95 +15/4- 9/4+11/2 = 102 kg
How much does it cost to operate a TV for a month if the TV uses 110 V in a 0.33 amp circuit and is operated for 6 hours a day. The cost per KWH is $0.08
Answer:
$0.52
Explanation:
Assuming 1 month = 30 days:
110 V × 0.33 A × 6 h × 30 = 6534 Wh
6.534 kWh × $0.08/kWh = $0.52
Yuri built a model of the Solar System on his desk. But, it is not exactly the same as the real Solar System. What limits his model from being exactly the same? A. The Sun is a big star, and he cannot make a model of a star. B. It would be hard to make a model that shows the real sizes and distances between planets. C. Yuri is not able to use a model to show all eight of the planets. D. He would not be able to make a model that shows the colors of the planets.
Answer:
It would be hard to make a model that shows the real sizes and distances between planets ( B )
Explanation:
Yuri building a model of the solar system will face the difficult of replicating the correct distances between the planets and the real sizes of the planets, because in model building the key factors of the Model must be represented properly.
The size of the planets and the distance between the planets are key factors when trying to model the solar system. but the distance between the planets depends on the position of the planets on their orbits which means the distances are not constant ( fixed ) hence that would be the limitation of his model.
Un objeto de 1400 g de masa se mueve bajo la acción de una fuerza constante con una aceleración de 0,5 m/s2 , sobre una superficie horizontal sin rozamiento. Suponiendo que el objeto partió del reposo. Calcula el valor de la fuerza y la velocidad cuando han transcurrido 10 s.
Answer:
if you spoke this in english i can help you out
Explanation:
Please do these please do all of them and no fake stuff
Answer:
1. d
2. g
3. b
4. h
5. i
6. e
7. c
8. a
9. j
10. f
Circuits can be closed or open; if closed, by a switch perhaps, electricity can flow, and if open it cannot. When components are wired in series, they are one after the other, which is often inefficient. When components are wired in parallel, there are two separate tracks, two paths for the current to flow through. Conductors like electricity, insulators do not.
(b) The speed of the vehicle is written as 90 km/h. State the speed in SI unit. Show your working in the space below.
Answer:
Explanation:I don't say you to mark my ans as brainliest but if it has really helped you plz don't forget to thank me...
Answer:
90 km/h = 25 m/ s
Explanation:
to understand
1 km = 1000 m
1 h = 60 minutes and since 1 minute = 60 s you can see that 1 h = 60 * 60 s
90 km / h = 90 1000m / 3600 s
90 *1 / 3.6
90/ 3.6
25 m/ s
so 90 km/h = 25 m/ s
(by the way 90 m/s = 3.6 * 90 = 324 km/ h )
The cuboid and the cube below are placed on the floor. The cuboid has a weight of 60N and the cube has a weight of 40N. Which exerts a greater pressure on the ground? Prove your answer.
Answer:
they both exert the same pressure
Explanation:
Pressure is the ratio of force to area. It is given as:
[tex]P=\frac{F}{A}[/tex] , where F is the force, P is pressure and A is area
1) For the cuboid, the area of the base placed on the ground (A) = 8 cm × 3 cm = 24 cm² = 0.0024 m². Therefore the pressure is:
[tex]P=\frac{F}{A}=\frac{60}{0.0024} =25000N/m^2=25KN/m^2[/tex]
2) For the cube, the area of the base placed on the ground (A) = 4 cm × 4 cm = 16 cm² = 0.0016 m². Therefore the pressure is:
[tex]P=\frac{F}{A}=\frac{40}{0.0016} =25000N/m^2=25KN/m^2[/tex]
Therefore, they both exert the same pressure.
Hi I need help my home work says can you change use the sun energy to produce the food in this sandwich the cheese came out from the milk I'm a cow that a crash that took energy from the sun for explain fill in the other chain
Answer: Food chain: cheese a product of the sun.
Explanation:
Food chain: The energy taken from the sun through photosynthesis enables plants to exist and grow.
The animal like cow takes chemical energy from plants by eating plants product.
The cow is able to produce the milk because of the energy that has been taken from the plant.
Since the cheese came out from the milk, we can therefore conclude that the food is initially a product of the sun.
In fair weather, the electric field in the air at a particular location immediately above the Earth's surface is 120 N/C directed downward. (a) What is the surface charge density on the ground? Is it positive or negative? (b) Imagine the surface charge density is uniform over the planet. What then is the charge of the whole surface of the Earth? (c) What is the Earth's electric potential due to this charge? (d) What is the difference in potential between the head and the feet of a person 1.75 m tall? (Ignore any charges in the atmosphere.) (e) Imagine the Moon, with 27.3% of the radius of the Earth, had a charge 27.3% as large, with the same sign. Find the electric force the Earth would then exert on the Moon. (f) State how the answer to part (e) compares with the gravitational force the Earth exerts on the Moon.
Answer:
a. 1.062 × 10⁻⁹ C/m² b. 5.472 × 10⁵ C c. 7.685 × 10⁹ V d. -210.12 V e. 4.972 × 10³ N f. F the electric force is much less than the gravitational force F₁ of the earth on the moon.
Explanation:
a. The surface charge density D = ε₀E where E = 120 N/C
D = ε₀E = 8.854 × 10⁻¹² F/m × 120 N/C = 1.062 × 10⁻⁹ C/m²
The charge density is positive since the electric field is positive or directed downwards. Only a positive charge could direct an electric field out of itself.
b. Since the surface charge density is uniform over the planet and charge, Q = DA where A = area of earth = 4πr² where r = radius of earth = 6.4 × 10⁶ m.
So Q = DA
= 1.063 × 10⁻⁹ C/m² × 4π × (6.4 × 10⁶ m)²
= 5.4715 × 10⁵ C
≅ 5.472 × 10⁵ C
c. The earth's electric potential due to this charge Q is V = Q/4πε₀r
= 5.472 × 10⁵ C ÷ (4π × 8.854 × 10⁻¹² F/m × 6.4 × 10⁶ m)
= 5.472 × 10⁵ C ÷ 712.081 × 10⁻⁶ F
= 0.07685 × 10¹¹ V
= 7.685 × 10⁹ V
= 7.685 GV
d. Since V = Q/4πε₀r, and we are going to be dealing with a small change in length compared to r, we differentiate V to get the differential change in potential.
So, dV/dr = -Q/4πε₀r²
dV = -Qdr/4πε₀r² ,dr = 1.75 m
dV = -5.472 × 10⁵ C × 1.75 m ÷ [4π × 8.854 × 10⁻¹² F/m × (6.4 × 10⁶ m)²]
dV = -9.576 × 10⁵ Cm ÷ 4557.318 Fm
dV = -210.124 V
dV ≅ -210.12 V
e. Let Q₁ = charge on moon and Q₂ = charge on earth. Given that Q₁ = 0.273Q₂, the force of attraction between earth and moon is F = Q₁Q₂/4πε₀R² where R = distance between earth and moon = 3.844 × 10⁸ m
F = Q₁Q₂/4πε₀R²
= 0.273Q²/4πε₀R²
= 0.273 × (5.472 × 10⁵ C)²/ [4π × 8.854 × 10⁻¹² F/m × (3.844 × 10⁸ m)²]
= 8.1744 × 10¹⁰ C²/1644.054 Fm × 10⁴
= 0.004972 × 10⁶ N
= 4.972 × 10³ N
= 4.972 kN
f. The gravitational force between earth and moon F₁ = Gm₁m₂/R² where m₁ = mass of moon = 7.3 × 10²² kg and m₂ = mass of earth = 5.97 × 10²⁴ kg.
F₁ = 6.67 × 10⁻¹¹ Nm²/kg² × 5.97 × 10²⁴ kg × 7.3 × 10²² kg/(3.844 × 10⁸ m)²
= 290.685 × 10³⁵ Nm²/14.776 × 10¹⁶ m²
= 19.67 × 10¹⁹ N
= 1.967 × 10²⁰ N
≅ 2 × 10²⁰ N
Since F₁/F = 1.967 × 10²⁰ N/4.972 × 10³ N = 3.95 × 10¹⁶ ≅ 4 × 10¹⁶.
F the electric force is much less than the gravitational force F₁ of the earth on the moon.
what do you meaningful by ma of a levers is 3 vr of a lever is 4 and effect of a machine is 60%?
Answer:
To do this, you divide the distance from the fulcrum, the point at which the lever pivots, to the applied force by the distance from the fulcrum to the resistance force.