Answer:
1) The kinetic energy of the object after it drops for 2.0 seconds is approximately 384.9 Joules
2) The potential energy of the object after it drops for 2.0 seconds is approximately 204 J
Explanation:
1) The given mass of the object, m = 2.0 kg
The height from which the object is dropped, h = 30 m
The kinetic energy of the object after it drops for 2.0 seconds = Required
Kinetic energy, K.E. = (1/2)·m·v²
Where;
v = The velocity of the object
The kinematic equation for finding the velocity of the object is presented as follows;
v = u + g·t
Where;
u = The initial velocity of the object = 0
g = The acceleration due to gravity of the object ≈ 9.81 m/s²
t = The time of motion of the object = 2.0 seconds
∴ The velocity after 2 seconds, v ≈ 0 + 9.81 m/s² × 2 s = 19.62 m/s
The kinetic energy, K.E. after 2 seconds as the object drops is given as follows;
[tex]K.E._{(after \ two \ seconds)}[/tex] = (1/2) × 2.0 kg × (19.62 m/s)² = 384.9444 J ≈ 384.9 J
2) The total energy, M.E. of the object at the top, h = 30 m, u = 0, is given as follows;
The total mechanical energy, M.E. = P.E. + K.E.
M.E. = m·g·h + (1/2)·m·u²
∴ M.E. = 2.0 kg × 9.81 m/s² × 30 m + 0 = 588.6 J
M.E. = 588.6 J
Given that the total mechanical energy, M.E., is constant, we have;
At 2.0 seconds, M.E. = 588.6 J , K.E. ≈ 384.9 J, P.E. = M.E. - K.E.
∴ P.E. = 588.9 J - 384.9 J ≈ 204 J
The potential energy after it drops 2.0 seconds, P.E. ≈ 204 J
The mass of an object is 4G and it has a density of 5gm^-3. what is the volume
Explanation:
Density is mass in grams over volume in cubic centimeters.
So it is
[tex]\frac{4g}{5cm^{-3} }[/tex] = 0.8 g/cm[tex]^{3}[/tex]
The unit is grams per cubic centimeter.
NB - density can also be kilograms over cubic meters
Momentum is a quantity that we say is typically _______________ in collisions.
A. Conserved
B. Lost
C. Disappeared
D. Gained
Momentum is a quantity that we can say is typically conserved in collisions.
Momentum is the quantity that that we see typically conserve in the collision,therefore the correct answer is the option A
It is the type of collision in which the total momentum as well as the kinetic energy on the system is conserved .The momentum before the collision is equal to the momentum after the collision in other words one can say in the elastic collision momentum of the quantity is conserved.
In the inelastic collision the momentum is conserved but the kinetic energy of the quantity is not conserved.
Momentum of a quantity is conserved irrespective of the type of collision whether it will be elastic collision or inelastic collision the momentum of the quantity will always be conserved.
Hence,we can say that momentum is the quantity that is conserved in collision,The correct answer for the given problem is option A.
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the gravitational force between two masses at distance of 2.5×10^6 metre is 250 Newton . what should be distance between them to reduce the gravitational force by half?
Answer:
distance between should be 1.25 × 10^6 m
Explanation:
Force is proportional to separation distance.
[tex]250 \: newtons = 2.5 \times {10}^{6} \: metres \\ ( \frac{1}{2} \times 250) \: newtons = d \\ \\ d = \frac{125 \times 2.5 \times {10}^{6} }{250} \\ d = 1.25 \times {10}^{6} \: metres[/tex]
Answer:
distance between should be 1.25×10^6.
Explanation:
force Is proportional to separation .
mrk above answer branilest .
What do is mean by environment friendly behaviour?
Define SI units. Also mention their importance. SI unit The
Answer:
SI unit is an internationally accepted system and have the same value all over the world .
I don't know the importance sotry
Answer:
SI unit is an internationally accepted system that have same value all over the world.
there is a dropping of a coconut of 2kg mass. the speed of the coconut at the moment before it hits the ground is 40m s-1.
calculate the kinetic energy of the coconut at the moment.
We know
[tex]\boxed{\sf K.E=\dfrac{1}{2}mv^2}[/tex]
m denotes to mass v denotes to velocity[tex]\\ \sf\longmapsto K.E=\dfrac{1}{2}\times 2\times 40^2[/tex]
[tex]\\ \sf\longmapsto K.E=40^2[/tex]
[tex]\\ \sf\longmapsto K.E=1600J[/tex]
Please help me. I need this in a few hours.
Answer:
A) The population of prey is greater than that of predator
What is 98.907 rounded to 1 significant figure?
The answer to the digits rounded to one significant figure is 100.
Significant figures are the most important figures in a number of digits.
The closer a digit is to the beginning of a number, the more important or significant it is.
But, the rule for rounding up a set of numbers to the first significant or to one significant figure is that:
If the next number is 5 or more, we round up.If the next number is 4 or less, we do not round up.From the numbers 98.907, 9 is the most significant digit followed by 8.
8 is greater than 5 so we should round up by adding one to 9 making the number 100.
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If the box of 500N is placed over the land of area of 2m²,what pressure is experted by the box on the land?
Answer:
250 Pa or N/m^2
Explanation:
Pressure(P)=F/A=500/2=250 Pa or N/m^2
Why is velocity proportial to pressure?
Answer:
Pressure and velocity are inversely proportional to each other because if pressure increase, the velocity decrease to keep the algebraic sum of potential energy, kinetic energy and pressure constant.
A man stands still on a moving walkway that is going at a speed of 0.2 m/s to
the west. What is the velocity of the man according to a stationary observer?
A. 0.2 m/s north
B. 0.2 m/s west
C. 0.2 m/s South
D. 0.2 m/s east
When,a man stands still on a moving walkway that is going at a speed of 0.2 m/s to the west,then the velocity of the man according to a stationary observer would be 0.2 m/s west,Therefore, the correct answer would be option B.
What is Velocity?The total displacement covered by any object per unit of time is known as velocity. The velocity of an object is depend on the magnitude as well as the direction of the object.
the mathematical expression for velocity is given by
velocity = total displacement /time
The speed and velocity of the object are very different from each other because speed does not depend upon the direction of the moving object but velocity depends on the magnitude of speed as well as the direction of the moving object.
As per given in the problem a man stands still on a moving walkway that is going at a speed of 0.2 m/s to the west therefore from the perspective of a stationary observer the velocity of man would be 0.2 m/s towards West.
Hence the correct options for the problem would be option B.
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300 ml of a gas at 27°C is Cooled at -3°c at Constant pressure the final volume is plzz answer fast i will mark brainliest
Answer:V₁=300ml
T₁=27°C
V₂=?
T₂= -3°C
as we know
V₁T₁=V₂T₂
By putting values in formula
300ml×27°C=V₂×(-3°C)
300ml×27°C/-3°C=V₂
8100ml/-3=V₂
-2700ml=V₂
or V₂= -2700ml
what is volum?Write its SI unit.write the si unit mass and length.
Explanation:
Volume is the quantity of three-dimensional space enclosed by a closed surface
The si unit of mass is kilogram (kg) and the si unit of length is metre(m)
The moon Phobos orbits Mars
(mass = 6.42 x 1023 kg) at
a distance
of 9.38 x 106 m. What is its period of
orbit?
[?]s
Answer:
Explanation:
We are basically needing to solve for the time in the equation d = rt, where d is the distance around Mars (aka the circumference), r is the velocity, and t is time. We need to find the circumference and the velocity. We will begin with the velocity.
Because the gravitational attraction between Phobos and Mars provides the centripetal acceleration necessary to keep Phobos in its (sort of) circular path, the equation we use for this is:
[tex]F_g=F_c[/tex] which says that Force supplied by gravity is equal to the centripetal force. Expanding that:
[tex]\frac{Gm_{Phobos}m_{Mars}}{r^2}=\frac{m_{Phobos}v^2}{r}[/tex]
When we move that around mathematically to solve for the velocity value, what we end up with is:
[tex]v=\sqrt{\frac{Gm_{Mars}}{r}[/tex] and filling in:
[tex]v=\sqrt{\frac{(6.67*10^{-11})(6.42*10^{23})}{9.38*10^6} }[/tex] and we get that
v = 2100 m/s
Now for the circumference:
C = 2πr and
C = 2(3.1415)(9.38 × 10⁶) so
C = 5.9 × 10⁷
Putting that all together in the C = vT equation:
5.9 × 10⁷ = 2100T so
T = 2.8 × 10⁴ sec or 7.8 hours
HELP!!
A particular electric car is supplied with 300 kJ of chemical energy by the battery. Of this, a total of 70.5 kJ of energy is wasted as heat.
Calculate the overall efficiency of the electric car.
[tex]\\ \sf\longmapsto 300-70.5=229.5kJ[/tex]
We know
[tex]\boxed{\sf Efficiency=\dfrac{Used\:Energy}{Supplied\:Energy}\times 100}[/tex]
[tex]\\ \sf\longmapsto Efficiency=\dfrac{229.5}{300}\times 100[/tex]
[tex]\\ \sf\longmapsto Efficiency=\dfrac{229.5}{3}[/tex]
[tex]\\ \sf\longmapsto Efficiency=76.5\%[/tex]
help me with this one
Answer:
may be d)45°
Explanation:
when an apple falls towards the earth the earth moves up to meet the apple. Is it true? If yes, why is the earth motion not noticeable ?
Answer:
Yes, this is true.
-- While the apple is falling, the same gravitational force acts on both the apple and the Earth.
-- The mass of the apple is somewhere in the neighborhood of 1/4 kg.
-- The mass of the Earth is about 5.972 x 10²⁴ kg.
-- Since the Earth has roughly 2.389 x 10²⁶ times as much mass as the apple has, the apple has roughly 2.389 x 10²⁶ greater acceleration than the Earth has, and moves roughly 2.389 x 10²⁶ times as far down as the Earth moves up, before they smack together.
-- That's why you don't notice the Earth's motion.
-- Also, you're standing on the Earth, moving up with it, toward the apple. Maybe it would be different if you were sitting on the apple, riding it down to the ground, and you were able to notice the motion of the ground coming up to meet you at a speed that's 0.00000000000000000000000000419 of YOUR speed.
Answer From Gauth Math
what is the role of the communicator in a dc generator?
A) it keeps the electric current flowing in one direction
B) it keeps the magnetic fields of the permanent magnet steady
C) it causes the magnetic fields of the permanent magnets to reverse
D) it causes the electric current to constantly reverse its direction
Answer:
C
Explanation:
Answer:
A)
Explanation:
it keeps the electric current flowing in one direction
A bullet of mass of 50g is moving with the velocity of 200km/h .calculate the kinetic energy of the bullet .
Answer:
is 10³
Explanation:
cuz the formula of KE is 1/2mv²
covert 50g to kg first then plug in the formula
1/2 × 0.05 × 200 = 10³ J
define one standard kg
Answer:
The mass of platinum iridium rod whose diameter and height are equal an kept at international bureau of weight and measurement in Paris of France is called as one standard kg.
A sample of Radon-222 has a half-life of 3.82 days. After 11.46 days, there is 5 grams of Radon-222 remaining. How much Radon-222 was in the original sample?
30 grams
2 grams
15 grams
40 grams
4 A student says that he has made a magnetic field with some iron filings. What would
you say to him?
Answer:
Yes but no
Explanation:
Here the kid cant say that he has created s magnetic field as iron fillings do not have magnetic properties
Define electric current and drift velocity.
Answer:
Current- the flow of free charges, such as electrons and ions
Drift velocity- the average speed at which these charges move
Answer:
An electric current is the stream of changed particals, such as electrons & ions, moving through an electrical conductor.
The average velocity attained bycharged partical ,such as electrons,in a material due to electric fields
Which is an example of current electricity?
Answer:
D
Explanation:
i just did it trust me
The unit of work in terms of Newton and metre is _______
Answer:
Joule
Explanation:
the unit of work is Joule determined by the letter J.
Answer:
JouleExplanation:
Joule is defined as the work done by a force of one newton causing a displacement of one meter. Sometimes, newton-metre (N-m) is also used for measuring work.
Two solid cubes have the same Mass but their edges are in the ratio of 4:1. What isthe ratio of their densities?
Let m be the mass of both cubes. If the smaller cube has side length x, then its volume is x ³. The side lengths of the larger cube have length 4x, so the larger cube's volume is (4x)³ = 64x ³, or 64 times as large as the smaller cube.
The first cube has a density of m/x ³, while the larger one has a density of m/(64x ³) = 1/64 m/x ³, so the ratio of densities is (1/64):1, or 1:64 (larger cube to smaller cube).
define inertia.mention it's types
Answer:
It is the inability of the body to change by itself its state of rest or uniform motion or direction. Types of Inertia- It is of three types-(1)Inertia of rest (2) Inertia of motion(3) Inertia of direction. (1) Inertia of rest - It is the inability of the body to change by itself its state if rest.
define simple machine
Answer:
simple machine, any of several devices with few or no moving parts that are used to modify motion and the magnitude of a force in order to perform work. ... The simple machines are the inclined plane, lever, wedge, wheel and axle, pulley, and screw.
what is the relation between centre of gravity and stability
Explanation:
tilting it will raise the height of its center of gravity.
The capacity of an RD bottle is 100 cc and its mass is 45 g. Find the mass of the bottle when it is filled with a liquid of density 600 kg/m3.
Answer:
The capacity of an RD bottle is 100cc and its mass is 45g. Find the mass of the bottle when it is filled with a liquid of density 600kg/[tex]m^{3}[/tex]
EXPLANATION:
100cc=100[tex]cm^{3}[/tex]
density of liquid=600Kg/ =0.6gm/
so mass of 100cc liquid will be m=d×V=0.6×100=60gm
So mass of bottle filled with liquid will be bottle+liquid=45gm+60gm=105gm
Answer is 105gm.
