Answer:
temperature is the degree of heat in a item or object and is measured by a thermometer.
Explanation:
help help help help help help help help help
An ice skater of mass 82 kilograms stands at rest in her skates on the ice rink. Someone throws a 5-kg ball at her at a speed of 17.4 m/s and she catches it. At what speed will she(and the ball) slide backwards?
Answer:
1 m/s
Explanation:
I showed my work in the picture attached.
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She slide(and the ball) backwards at the speed of 1m/s when she catches the ball of 5-kg coming at speed of 17.4 m/s.
What is momentum ?Momentum is defined as mass times velocity. it tells about the moment of the body. it is denoted by p and expressed in kg.m/s. mathematically it is written as p = mv. A body having zero velocity or zero mass has zero momentum. its dimensions is [M¹ L¹ T⁻¹].
Momentum is conserved throughout the motion.
According to conservation law of momentum initial momentum is equal to final momentum.
Given,
mass of the skater m₁ = 82 kg
mass of the ball m₂ = 5kg
initial velocity of the ball v'₂ = 17.4 m/s
initial velocity of the skater v''₂= v'₁= 0
final velocity of the ball & skater = v''₁ = ?
According to law of conservation of momentum,
initial momentum = final momentum
m₁v'₁ +m₂v'₂ = m₁v₁'' + m₂v''₂
putting all values in the equation.
0+ 5×17.4 = 82×v₁'' + 5×v₁''
v₁''(82+5) = 87
v₁'' = 1 m/s
Hence he(and the ball) slide backwards at 1m/s
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Friction produces heat because it causes molecules to move faster and
have more energy.
True or false.
Answer:
True
Explanation:
Friction occurs because no surface is perfectly smooth. Even surfaces that look smooth to the unaided eye make look rough or bumpy when viewed under a microscope. You know that friction produces heat. That’s why rubbing your hands together makes them warmer. But do you know why? Friction causes the molecules on rubbing surfaces to move faster, so they have more energy. This gives them a higher temperature, and they feel warmer. Heat from friction can be useful. It not only warms your hands.
If you started counting from 1st grade, how many years of education would the typical professional astronomer have today, at minimum?
12
14
16
18
16 years of education would the typical professional astronomer have today, at minimum
what are the basic qualification needed for astronomer ?Minimum qualifications of Astronomer 4 year degree to get a postgraduate qualification like a master of physics.
2 or 3 A levels of math and physics; 5 GCSEs at grades 9 to 4 (A* to C), or equivalent; and a degree in a field that is useful for postgraduate are needed.
Math and physics expertise needed, analytical thinking abilities, science knowledge, great verbal communication skills, and the capacity to think coherently both logic and reasoning are all essential.
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What attitudes and actions can group leaders take in trying to establish trust within a group during the initial stage of group development? How is each attitude and action important in the process of initiating trust?
Answer:
i dont know!
Explanation:
Which of the following has the most kinetic energy?
A.
A car traveling at 80 kph.
B.
A tractor trailer traveling at 80 kph.
C.
A cheetah running at 80 kph.
D.
A notorcycle traveling at 80 kph.
Answer:
B
Explanation:
A tractor is the heaviest
Which of the following objects most likely has a constant speed?
A car that speeds up when the light turns green
A car traveling at 65 mph on the freeway
A car that slows down to a stop due to a red light
A car that makes a u-turn
The density of water is 1.0g/cm3. How many kilograms of water does a submerged 120-cm3 block displace? Recall that 1.0 kg weighs 9.8 N on Earth. What is the buoyant force on the block?
Answer:
The mass of the liquid displaced is 0.12 kgThe buoyant force on the block is 1.176 N.Explanation:
Given;
density of water, ρ = 1.0 g/cm³
volume of the submerged block, V = 120 cm³
Applying Archimedes principle;
The mass of the liquid displaced is calculated as;
m = ρV
m = 1.0 g/cm³ x 120 cm³
m = 120 g
m = 0.12 kg
The buoyant force on the block is calculated as;
F = mg
F = 0.12 x 9.8
F = 1.176 N
Therefore, the buoyant force on the block is 1.176 N.
3. It takes at least 4 people to push a refrigerator up a 10-meter ramp. How many people would be needed to push the same refrigerator to the same height using a
20-meter ramp? (Assume no friction for both ramps.)
O A. at least 2 people
O B. at least 4 people
O c. at least 8 people
D. Not enough information (could be impossible).
.
Answer:
A
Explanation: Using a ramp that is twice is long (and therefore flatter) means that half as much force is needed. Force is provided by the people who push, so only half as many people would be needed.
At least 2 people would be needed to push the same refrigerator to the same height using a 20-meter ramp.
Given the following data:
Number of people = 4 people.Height A = 10 meters.Height B = 20 meters.What is a ramp?A ramp can be defined as a sloping plane or surface that is typically used to connect two (2) levels; a higher and a lower level.
In this scenario, a ramp that is twice as long as the first ramp was used to push a refrigerator up. This simply means that, half the magnitude of force provided by the 4 people pushing the refrigerator up a 10-meter ramp would be needed for the 20-meter ramp, assuming no friction for both ramps.
In conclusion, we can deduce that at least 2 people would be needed to push the same refrigerator to the same height using a 20-meter ramp.
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how deep is the event horizon
Explanation:
The supermassive black holes that the Event Horizon Telescope is observing are far larger; Sagittarius A*, at the center of the Milky Way, is about 4.3 million times the mass of our sun and has a diameter of about 7.9 million miles (12.7 million km), while M87 at the heart of the Virgo A galaxy is about 6 billion solar ..
Calculate the amount of potential difference in a capacitor of 0.9 MF , If the amount of charge is 1.4x10^-4 C .(Show all the work)
Answer:
Potential difference [tex]V=1.6\times 10^{-10}\ V[/tex]
Explanation:
Capacitance of capacitor, C = 0.9 MF
Charge, [tex]Q=1.4\times 10^{-4}\ C[/tex]
We need to find the amount of potential difference. We know that,
[tex]Q=CV[/tex]
V is potential difference
So,
[tex]V=\dfrac{Q}{C}\\\\V=\dfrac{1.4\times 10^{-4}}{0.9\times 10^6}\\\\V=1.6\times 10^{-10}\ V[/tex]
So, the required potential difference is [tex]1.6\times 10^{-10}\ V[/tex].
Problem 3 (a) Assuming the human body (skin temperature 34◦C) to behave like an ideal thermal radiator, find the wavelength where the intensity from the body is a maximum. In what region of the electromagnetic spectrum is radiation with this wavelength? (b) Making whatever (reasonable) assumptions you may need, estimate the power radiated by a typical person isolated from the surroundings. (c) Estimate the radiation power absorbed by a person in a room in which the temperature is 20◦C.
Answer:
Explanation:
a )
We shall apply Wein's displacement law
λm x T = b where λm is wavelength of radiation having maximum intensity
T is absolute temperature of body , and b is a constant
b = 2898 μm-K
T = 273 + 34 = 307 K
λm x 307 = 2898
λm = 9.44 μm
= 9440 nm
It is infrared radiation .
b )
We shall apply Stefan's law of radiation.
E = σA T⁴
E is emitted radiation by body acting as black body , A is surface area , T is absolute temperature of body
σ = 5.67 x 10⁻⁸ J / m²T⁴
Surface area of a typical man's body A = 1.9 m²
T = 273 + 34 = 307 K
Assuming human body as black body
E = 5.67 x 10⁻⁸ x 1.9 x 307⁴ J/s
= 9.57 x 10² J/s
= 957 W .
c )
Radiation absorbed
E = 5.67 x 10⁻⁸ x 1.9 x ( 273 + 20 )⁴ J/s
= 794 W .
Similarities between football and badminton ?
Answer:
Explanation:
Football and badminton enquire you use your lems and you would need equipment
Football and badminton enquire you use your legs and you would need equipment.
What are the similarities between badminton and tennis?Similarities of Tennis & Badminton both are racket sports. both video games consist of a net in which the ball/shuttlecock needs to be hit over the internet to the opponent's court which will win the point. Both video games have guys singles, guys doubles, girls singles, girls doubles, and combined doubles categories.
Each game and sports activities have hard and fast policies, which ensure honest opposition. they may involve teams or individual competitions. Human beings play video games and sports for activity and amusement, but in addition, they benefit from numerous skills and understanding via video games and sports activities.
While soccer is played through feet, handball is a game played by using hand. Both sports have some similarities which consist of the function of the goalkeeper who can play with ft and arms in the strive of saving the ball from attaining the purpose.
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in solid conductors, what is responsible for the flow of electrical current??
Answer:
Ussually, soft metals. or solid objects that allow the flow of eletrons.
Explanation:
Electric Current is the flow of electrons through a wire or solution. In a solid the electrons are passed from one positively charged metallic atom to next but in solution the electron is carried by the ions present in the solution. A solution capable of carrying charge is called an electrolyte.
In solid conductors, electron mobility is responsible for the flow of electrical current.
Electron mobility is principally responsible for the flow of electrical current in solid conductors. The subatomic particles known as electrons orbit the atomic nuclei of atoms and are negatively charged. The outermost energy levels of the atoms in a solid conductor, such as a metal like copper or aluminum, have numerous free or loosely bound electrons.
The conductor experiences an electric field that pulls on the free electrons when an electric potential difference (voltage) across its ends is applied (for example, by connecting it to a battery or power source). The electrons are propelled by this force toward the direction of the electric field.
Hence, in solid conductors, electron mobility is responsible for the flow of electrical current.
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Could I please get some help on this question I don’t understand .
Answer:
12.5 m/s
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 0 m/s
Height (h) = 8 m
Final velocity (v) at 8 m above the lowest point =?
NOTE: Acceleration due to gravity (g) = 9.8 m/s²
The velocity of the roller coaster at 8 m above the lowest point can be obtained as follow:
v² = u² + 2gh
v² = 0² + (2 × 9.8 × 8)
v² = 0 + 156.8
v² = 156.8
Take the square root of both side
v = √156.8
v = 12.5 m/s
Therefore, the velocity of the roller coaster at 8 m above the lowest point is 12.5 m/s.
what is a likely consequence of continued human population growth
Answer:
Rapid human population growth has a number of consequences. Population grows fastest in the world's poorest countries. High fertility rates have historically had a strong relation with poverty, and high childhood mortality rates
Explanation:
i got it from goo.gle but i hope that helps:)
have a good day bro
So Fn = dº* p*g What would happen to the force (FN) if the size of each side of the cube were to double? d -> 2d
Answer:
Fn=m(a + g) :
Explanation:
nf=a(m +g)
an=f(g+m)
flint glass materials
Answer:
Flint glass is combination of silicon dioxide (SiO2) with lead or potassium. It creates a relatively high refractive index and high degree of light dispersing power compared to other types of glass.
Explanation:
:)
Answer:Flint glass is combination of silicon dioxide (SiO2) with lead or potassium. It creates a relatively high refractive index and high degree of light dispersing power compared to other types of glass.
Explanation:
Which statement can be supported by using a position-time grap
O A negative slope results when an individual is moving away
O A horizontal line on the graph means the individual is moving
O A positive slope results when an individual is moving away fr
O The speed of an individual cannot be determined from this ty
Answer:
A negative slope results when an individual is moving away
Explanation:
A parcel has a mass of 500 g .calculate its weight (assume the gravitational field strength is 10 N/Kg
Answer:
5N
Explanation
convert grams to kg and multipy with 10 (.5 *10)=5N
7. An electric kettle is connected to a mains voltage of 230 V. The current in the kettle is 12 A. Calculate the power of the kettle
Answer:
2,760watts
Explanation:
Power of the kettle = current * voltage
P = IV
Given
I = 12A
V = 230V
Substitute into the formula
Power of the kettle = 12*230
Power of the kettle = 2,760watts
This circuit has more than one loop. When one light goes out, the
others stay on.
A.open circuit
B.series circuit
C.parallel circuit
D.closed circuit
Answer:
Parallel circuit
Explanation:
A parallel circuit has a direct current allowing it to go back and forth making it have more pathways and loops. if one light bulb goes out the pathways will allow the electricity to still flow inti the other light bulbs.
What is the equation of the line that is perpendicular to y= -4x +5 and passes through the point (4,-3)?
What energy transfer happens in many musical instruments?
Sound to kinetic
Electrical to kinetic
Kinetic to sound
Answer:
kinetic to sound
Explanation:
this is because energy is moving in the instrument and it produces sound.
Write the word conductor or insulator on each of the lines. Then infer which type of material is inside the holes in the outlet. Explain you answer.
( will mark brainliest if you help.)
The required choice is for both the lines are conductor and conductor.
What is conductor and insulator?A conductor is something that easily allows current to flow through it. As an example, consider metal or any other metal. An insulator is something that does not allow current to travel through it. Polyurethane is an example.
Here,
Inside each socket are two pairs of metal strips that are engineered to bend and flex but return to their original shape when pressure is released. Each pair of strips is linked to one of your power lines (either hot or ground).
When you insert the wall plug, springy brass fingers hold the plug prongs, allowing you to connect to your home's electrical system.
Thus, the required choice is for both the lines to be conductor and conductor.
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1. What is the equivalent resistance in this circuit?
2. What is the current in this circuit?
1. The equivalent resistance in a series circuit, like the one shown, is given by the general equation
[tex]R_{S} = R_1 + R_2 + R_3 + . . . + R_{N-1} + R_N = \sum_{i=1}^N R_i[/tex]
where N is the number of resistors in series. Here, there are four resistors in series. Using our equation with N = 4, we obtain
[tex]R_{S} &= R_1 + R_2 + R_3 + R_4 \\ R_{S} = 2.0 \, \Omega + 3.0 \, \Omega + 4.0 \, \Omega + 6.0 \, \Omega \\ R_{S} = 15.0 \, \Omega.[/tex]
2. The current in this series circuit is equal to the voltage divided by the equivalent resistance (a relationship you can derive from Ohm's law):
[tex]I = \frac{V}{R_{S}} = \frac{45 \, V}{15.0 \, \Omega} = 3.0 \, A. \nonumber[/tex]
Help me guys please
Answer:
The answer is B
Explanation:
keep it up
A train travels between two stations that are 63 km apart at an average speed of 35 m/s. How long after leaving the first station did the train arrive at the second station?
A train travels between two stations that are 63 km apart at an average speed of 35 m/s. Time taken by train after leaving the first station and arrive at the second station 1.8 sec.
What is speed?The speed of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a scalar quantity.
time = Distance / speed
= 63/35.
= 1.8 sec
A train travels between two stations that are 63 km apart at an average speed of 35 m/s. Time taken by train after leaving the first station and arrive at the second station 1.8 sec.
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What is the frequency of a wave that has a wavelength of 0.20 m and a speed of 22 m/s
Answer:
The frequency of the wave would come out to be 110 Hz.
Frequency is the number of completed wave cycles per second. By using the simplest frequency equation, f = 1 / T, you get the answer I provided above.
if a given wave has a frequency of 7.7 Hz, find how long it takes for one of these waves to pass a given point. (find the period)
Answer:
Period = 0.1 seconds
Explanation:
Given the following data;
Frequency = 7.7 Hz
To find the period;
[tex] Period = \frac {1}{Frequency}[/tex]
[tex] Period = \frac {1}{7.7}[/tex]
Period = 0.1 seconds
Therefore, it would take one of these waves 0.1 seconds to pass a given point.