Answer:
Magnets work by using Earth's magnetic pull.
Explanation:
Magnets move objects because they are made of steel or metal. And for that reason, they can stick to objects that are metal.
A 50 g sample of an unknown metal is heated to 90.0C. It is placed in a perfectly insulated container along with 100 g of water at an initial temperature of 20C. After a short time, the temperature of both the metal and water become equal at 25C. The specific heat of water is 4.18 J/gC in this temperature range. What is the specific heat capacity of the metal?
Record your answer with two significant figures.
5.98
J/gC
Answer:
0.64 J/g°C
Explanation:
Using the formula;
Q = m × c × ∆T
Where;
Q = amount of heat
m = mass (g)
c = specific heat capacity
∆T = change in temperature (°C)
In this case:
Q (water) = - Q (metal)
mc∆T (water) = - mc∆T (metal)
According to the information in this question,
For water; m = 100g, c = 4.18J/g°C, ∆T = (25°C - 20°C)
For metal; m = 50g, c =?, ∆T = (25°C - 90°C)
mc∆T (water) = - mc∆T (metal)
100 × 4.18 × (25°C - 20°C) = - {50 × c × (25°C - 90°C)}
100 × 4.18 × 5 = - {50 × c × -65}
2090 = -{-3250c}
2090 = 3250c
c = 2090/3250
c = 0.643
c = 0.64J/g°C
Answer:
0.64
Explanation:
Because I got the question right :)
1. How much work is done in lifting an 8-kg box
from the floor to a height of 2m above the
floor?
Answer:
156.8 Joules
Explanation:
Work = Force x Displacement
Displacement = 2m
Force (force of gravity) = mass x acceleration due to gravity = 8Kg x 9.8m/s^2
= 78.4N
Work = FxD
Work = 78.4 N x 2m
Work = 156.8 N·m OR 156.8 Joules
The amount of work done in lifting this box is equal to 156.8 Joules.
Given the following data:
Mass = 8 kilograms.Displacement = 2 meters.Scientific data:
Acceleration due to gravity = 9.8 [tex]m/s^2[/tex]To calculate the amount of work that is done in lifting this box:
How to calculate work done.Mathematically, the work done by a person is calculated by using this formula:
[tex]Work\;done = Fd = mgd[/tex]
Where:
F is the force.d is the displacement.m is the mass.Substituting the given parameters into the formula, we have;
[tex]Work\;done = 8 \times 9.8 \times 2[/tex]
Work done = 156.8 Joules.
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How many moons are in our solar system?
Can anyone prove ADIABATIC PROCESS ???
Answer:
The adiabatic process can be derived from the first law of thermodynamics relating to the change in internal energy dU to the work dW done by the system and the heat dQ added to it. The word done dW for the change in volume V by dV is given as PdV. Hence, the equation is true for an adiabatic process in an ideal gas.
Explanation:
Hope it helps......bro
4) Which is the BEST description of a tectonic plate? *
O A. Tectonic plates consist of the lithosphere and part of the asthenosphere.
O B.Tectonic plates are large pieces of mesosphere that never move.
C. Tectonic plates are large pieces of lithosphere that move on tope of the
asthenosphere.
O D. None of these answers is correct.
Answer:
The answer is A
Explanation: i took k12
If you wear knee pads while skating,It will take three times as long for you to come to rest when you fall and land on your knees. how does this affect the impulse applied to your knees when you fall?
The long time will decrease the velocity which will equally decrease the impulse applied to your knee.
What is impulse?
The impulse experienced by an object is the change in momentum of the object.
J = ΔP = m(v - u)
where;
J is impulseΔP is change in momentumm is mass of the bodyv is final velocityu is initial velocityv = distance / time
when time of fall becomes 3 times long, the final velocity becomes 3 times smaller
Since the velocity will be reduced, the impulse applied to your knee will decrease as well.
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I NEED ANSWER ASAP!!!
At which point(s) will acceleration occur shown in the image???
Answer:
Gravity is an ever present force, and therefore acceleration is guaranteed to happen at every single one of those points (and in fact, everywhere in the universe).
On top of that, friction will be present in all four spots (friction with the rails, with the air, with the axles, etc.), and friction is a perfectly acceptable force that will cause acceleration, slowing the roller coaster down.
So the correct answer is every single point, regardless of what answer the teacher expects.
The object will be moving faster if the acceleration and velocity are pointing in the same direction. The object will also slow down if the acceleration is pointing in the opposite direction as the velocity.
What role of acceleration in the motion of object?When an object's speed, direction of motion, or both change, it accelerates. Even while it may appear to be virtually immediate in some circumstances, such as when a golf ball is struck by a club or during car collisions, changes in an object's speed are always continuous.
Since gravity is a constant force, acceleration will unavoidably occur at each of those locations and throughout the whole universe.
Therefore, In addition, there will be friction at all four locations—friction with the axles, the air, the rails, etc.—and friction is a completely normal force that will accelerate the roller coaster, slowing it down.
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Which process enables the boy to see over the wall?
Answer: yeah it is reflection
Answer:
C
Explanation:
A glass test tube rubbed with silk and an acrylic rod rubbed with a paper towel become charged due to the process of charging by friction. How do the test tube and rod interact?
Answer:
Attraction.
Explanation:
Charging by friction involves rubbing of objects against one another so that one loses electron(s), while the other gains the electron(s). Thus, the objects would have opposite charges after the process.
The glass test tube rubbed with silk loses electron, thus becomes positively charged. While the acrylic rob rubbed with paper towel becomes negatively charged. Since the two rods have opposite charges, then the interaction between them would be attraction. A force of attraction between the rods would be experienced while the rods are brought to a required close range.
Sound wave W has amplitude ‘A' and frequency ‘f'. Sound wave X is louder and lower in pitch than sound wave W. What can be said about the amplitude and frequency of sound wave X?
Answer:
Sound wave X amplitude is greater than 'A' and its frequency is lesser than
'f'
Explanation:
The pitch of a sound is dictated by the frequency of the sound wave, while the loudness is dictated by the amplitude.
A high pitch sound corresponds to a high frequency and a low pitch sound corresponds to a low frequency.
The larger the amplitude of the waves, the louder the sound and vice-versa.
From the question,
Sound wave W has amplitude ‘A' and frequency 'f' and
Sound wave X is louder and lower in pitch than sound wave W.
Since sound wave X is louder, this means its amplitude is greater than 'A'.
Also, since sound wave X is lower in pitch, this means its frequency is lesser than 'f'.
Answer:
Higher than A, Lower than F
Explanation:
A 0.50-kilogram frog is at rest on the bank surrounding a pond of water. As the frog leaps from the bank, the magnitude of the acceleration of the frog is 4.0 meters per second².
Complete question:
A 0.50 kilogram frog is at rest on the bank surrounding a pond of water. As the frog leaps from the bank, the magnitude of the acceleration of the frog is 4.0 meters per second^2. Calculate The magnitude of the net force exerted on the frog as it leaps.
Answer:
2.0N
Explanation:
Given that,
Mass, m of the frog = 0.5 kg
The acceleration of the frog = 4.0 m/s².
We have been asked To find,
The magnitude of the net force exerted on the frog as it leaps.
So
We calculate this using the formula below :
F = ma
When we insert the values into the formula, we have:
F = 0.5 kg × 4 m/s²
F = 2.0 N
Therefore, the magnitude of net force is 2.0 N.
the earth rotates once every 24 hrs. a person in north america is 4.88*10^6 m from the earth's axis. what is the person's linear speed?
Answer:
The linear speed is approximately 354.88361 m/s
Explanation:
The given parameters are;
The time it takes the Earth to make one complete rotation = 24 hrs.
The distance of the location of the person in North America from the axis, r = 4.88 × 10⁶ m
The rotation per 24 hours = 1 rev/(24 h)
24 hours = 24 hours ×60 minutes/hour × 60 seconds/minute = 86,400 seconds
Therefore, we have, the rotation rate per second, n = 1 rev/(86,400 s)
The angular speed, ω = 2·π·(1 rev/(86,400 s)) ≈ 7.2722052 × 10⁻⁵ rad/s
The linear speed, v = ω × r
Therefore, v ≈ 7.2722052 × 10⁻⁵ rad/s × 4.88 × 10⁶ m = 354.88361 m/s.
The linear speed, v ≈ 354.88361 m/s.
A tennis ball is served horizontally from 2.4m above the ground at net is 12m away and point 0.9 high will be ball clear the net where will be ball land
Explanation:
Let us first calculate long does it take to go 12m at 30m/s( assumed speed)
12/30 = 0.4 seconds
horizontal distance the ball drop in that time
H= (0)(0.4)+1/2(-9.8)(0.4)2
H= -0.78m
negative sign shows that the height of the ball at the net from the top.
Height of the ball at the net and from the ground= H1-H=2.4-0.78=1.62m
As 1.62m>0.9m so the ball will clear the net.
H_1= V0y t’ + ½ g t’^2
-2.4= (0)t’ + ½ (-9.8) t’^2
t’= 0.69s
X’=V0x t’
X’=(30)(0.96)
X’= 20.7m
The driver of a 1.5 x 103 kg car is traveling east at 10 m/s and increases its speed to 30 m/s east over 15 seconds. What was the change in momentum of the car? Kgm/s
Answer:
30,000kgm/s
Explanation:
Change in momentum is expressed as;
Change in momentum = mass × change in velocity
∆M = m∆v
Mass m = 1.5×10³kg = 1500kg
∆v = 30-10 =20m/s
Substitute into the formula
Change in momentum = 1500(20)
Change in momentum = 30,000kgm/s
if a 1200kg car travels 20 m/s and slows down for a stop, what is its momentum?
Answer:
24000kgm/s
Explanation:
Given parameters:
Mass of car = 1200kg
Velocity = 20m/s
Unknown:
Momentum = ?
Solution:
Momentum is the amount of motion a body possesses.
Momentum = mass x velocity
Now insert the parameters and solve;
Momentum = 1200 x 20 = 24000kgm/s
explain how balanced and unbalanced forces effect an objects motion differently
Answer:
Balanced Forces will not change the object's motion.
Unbalanced Forces will change the object's motion.
Explanation:
A bowling ball of 35.2kg, generates 218 kg.m/s units of momentum. What is the velocity of the bowling ball?
Answer:
6.19m/s
Explanation:
Given parameters:
Mass of bowling ball = 35.2kg
Momentum = 218kgm/s
Unknown:
Velocity of the bowling ball = ?
Solution:
Momentum is the quantity of motion a body possess;
Momentum = mass x velocity
218 = 35.2 x velocity
Velocity = 6.19m/s
Both speed and velocity measure how fast something is moving. However, since speed is not a _ it does not require an _
Answer:
vector
direction
Explanation:
Both speed and velocity measures how fast something is moving. Since speed is not a vector, it does not require direction to describe it.
Speed is the distance divided by the time taken. It is a scalar quantity in that it has only magnitude but no direction.
When describing speed, there is no need to specify its direction.
But when describing velocity, we specify both magnitude and direction.
you have boasted to your friends that you can ride your bicycle at 30 KPH (KM per Hour) over a 30KM race track comprising of two 15km laps. However, when you finish the first lap, your coach tells you that your average is only 15 KPH. How fast must you ride to bring your average speed to 30 kph.
Answer:
faster than 100 kph
Explanation:
Time taken to complete the first lap is
[tex]\dfrac{15\ \text{km}}{15\ \text{kph}}=1\ \text{hour}[/tex]
If the person's average speed is to be 30 kph then the complete race would be over in [tex]\dfrac{30}{30}=1\ \text{hour}[/tex]
But 1 hour has passed in the first lap already so, the next 15 km must be covered in 0 time.
So, the speed of the bike must be more than 100 kph.
a manor house was most similar to
Answer:
I don't know the multiple choices or if you have any but my best answer is castle.
I hope this helps!
what are the importance of gravitation
Answer:
Gravity is very important to us. We could not live on Earth without it. The sun's gravity keeps Earth in orbit around it, keeping us at a comfortable distance to enjoy the sun's light and warmth. It holds down our atmosphere and the air we need to breathe.
Answer:
Newton's universal law of gravitation explains the attractive force between any two objects which have mass.It explains how we are able to stand on earth, why a body thrown up falls to the ground, why planets revolve around the sun and why the moon revolves around the earth, and so on.This law says that as the distance between two objects increases their force of attraction decreases. This explains why we are not pulled towards a distant star even though it is more massive than the Earth.This law leads to the derivation of an expresion for the acceleration due to gravity...With the help of gravitation, we can understand the force experience by various planets , stars etc. with each other.This law makes us understand why the planets revolve around the sun and why satellite revolve around the planets.Gravitation explains us how the planets are held by the sun and why don't they fall on it.It can also explain how tides are formed on earth. (Tides are due to the gravitational forces of the sun and the moon).Example:
Astronauts reach a distant planet and find it takes eight times as much force to lift objects there than it does on Earth. What is the acceleration due to gravity on this planet?
On this planet the force of gravity is eight times larger. Since the masses of objects are a fundamental property of those objects, they cannot change, that means the value of g must be eight times larger as well:
[tex]8F_{grav}=m(8g)8F[/tex]
[tex]=m(8g)[/tex]
The value of g on Earth is 9.8 m/s2, so 8 × 9.8 m/s2 = 78.4 m/s2.
why is the lake shallow in winter?
Answer:
The justification for this scenario has been characterized elsewhere here.
Explanation:
Water extraction becomes the platform that could be utilized to start managing the problems of aquatic weeds. Water level devaluations often begin throughout the fall as well as keep going via the cold season because once water entertainment will be at its lowest. This has managed to decrease coastal erosion throughout these heavy floods.How much force is needed to accelerate 250 kg at a rate of 6 m/s/s?
Answer:
[tex]1500 \: \mathrm{N}[/tex]
Explanation:
The equation [tex]F=ma[/tex] represents the force needed.
Plugging in [tex]m=250[/tex] and [tex]a=6\: \mathrm{m/s^2}[/tex], we find that the force needed to accelerate a 250 kg object at a rate of [tex]6 \: \mathrm{m/s^2}[/tex] to be [tex]\fbox{$1500 \: \mathrm{N}$}[/tex].
plz hurry
Which of the following is a result of sterilizing wounds with chemicals?
increased rate of infection
reduced need for hand-washing
reduced rate of infection
increased death rate
Answer:
Sterilization is a common medical practice It decreased bacterial bloom and coverage Hence it reduced rate of infectionIf you drop a steel metal ball off a building and it takes 3 seconds to hit
the ground, how tall is the building?
Answer:
[tex]40\:\mathrm{m}[/tex]
Explanation:
We can use kinematics equation [tex]\Delta y={v_i}^2+\frac{1}{2}at^2[/tex] to solve this problem. Because the metal ball's initial velocity was 0, [tex]{v_i}^2=0[/tex].
Therefore, our equation becomes:
[tex]\Delta y=\frac{1}{2}at^2[/tex] (freefall equation).
[tex]t[/tex] is given as 3 seconds and [tex]a[/tex] is acceleration due to gravity ([tex]9.81\:\mathrm{m/s}[/tex]).
Therefore, our answer is:
[tex]\Delta y = \frac{1}{2}\cdot9.81\cdot3^2=44.145=\fbox{$40\:\mathrm{m}$}[/tex] (one significant figure).
what is projectile. what is projectile motion
The projectile is any object thrown into space upon which the only acting force is gravity. In other words, the primary force acting on a projectile is gravity. This doesn’t necessarily mean that the other forces do not act on it, just that their effect is minimal compared to gravity. The path followed by a projectile is known as a trajectory. A baseball batted or thrown and the instant the bullet exits the barrel of a gun are all examples of the projectile.
Projectile Motion:When a particle is thrown obliquely near the earth’s surface, it moves along a curved path under constant acceleration that is directed towards the center of the earth (we assume that the particle remains close to the surface of the earth). The path of such a particle is called a projectile and the motion is called projectile motion. Air resistance to the motion of the body is to be assumed absent in projectile motion.
In a Projectile Motion, there are two simultaneous independent rectilinear motions:
Along the x-axis: uniform velocity, responsible for the horizontal (forward) motion of the particle.
Along y-axis: uniform acceleration, responsible for the vertical (downwards) motion of the particle.
Accelerations in the horizontal projectile motion and vertical projectile motion of a particle: When a particle is projected in the air with some speed, the only force acting on it during its time in the air is the acceleration due to gravity (g). This acceleration acts vertically downward. There is no acceleration in the horizontal direction, which means that the velocity of the particle in the horizontal direction remains constant.
[tex]\sf~~~~~~~~~~~~~~~{\red{\underbrace{\underline{\green{projectile~motion}}}}}[/tex]
Projectile motion is a form of motion in which object or particle is thrown near earth's surface and it moves along a curved path under the action of gravity only.
what volume of alcohol will have the same mass as 4.2m^3 of petrol? (density of alcohol 0.4kg/m^3 and petrol is 0.3kg/m^3)
Answer:
3.15m³
Explanation:
To solve this problem, let us first find the mass of the petrol from the given dimension.
Mass = density x volume
Volume of petrol = 4.2m³
Density of petrol = 0.3kgm⁻³
Mass of petrol = 4.2 x 0.3 = 1.26kg
So;
We can now find the volume of the alcohol
Volume of alcohol = [tex]\frac{mass}{density}[/tex]
Mass of alcohol = 1.26kg
Density of alcohol = 0.4kgm⁻³
Volume of alcohol = [tex]\frac{1.26}{0.4}[/tex] = 3.15m³
Help! 5 questions for 25 points? Seems fair Please help
Answer:
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Explanation:
Imagine a player throwing a football. Explain the action of what is happening to the hand and ball, as well as describe the action force and the reaction force
Answer:
Explanation:
When a player throws a football , he applies force on the ball , due to which ball accelerates in forward direction . This is the action force .
The ball also applies a force on the hand of the player . Due to it the player experiences a pushing force in backward direction . This is reaction force .
Due to this force , the player does not move in backward direction because of frictional force of the ground . The frictional force keeps him stationary .
A resultant force of 25 newtons acts on a mass of 0.50 kilograms starting from rest. Find the acceleration in m/s2 .
Answer:
[tex]50\:$\mathrm{m/s^2}[/tex]
Explanation:
From Newton's Second Law, recall [tex]F=ma[/tex].
Rearranging this equation, we have [tex]a=\frac{F}{m}[/tex]. [tex]F[/tex] is given as [tex]25\:\mathrm{N}[/tex] and mass given as [tex]0.5\:\mathrm{kg}[/tex].
Plugging in these values, we get:
[tex]a=\frac{25}{0.5}=\fbox{$50\:\mathrm{m/s^2}$}[/tex].
The rate change of direction or speed of the object is called acceleration. The acceleration of the given mass is 50 m/s².
Acceleration:
It is the rate change of direction or speed of the object. From the Newton's second law of motion,
[tex]\bold {a = \dfrac Fm}[/tex]
Where,
F - force applied = 25 N
m - mass = 0.5 kg
Put the values,
[tex]\bold {a = \dfrac {25}{0.5}}\\\\\bold {a = 50\ m/s^2}[/tex]
Therefore, the acceleration of the given mass is 50 m/s².
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