T=2 Hours 6 Minutes 33.53 Seconds
Sebastián se encuentra en una parada de trenes. El tren n° 15 pasa sin detenerse a una velocidad de 35 km/h. Si situamos el sistema de referencia en Sebastián, ¿el tren n° 15 está en reposo o en movimiento?
Answer:
the train is moving relative to the boy
Explanation:
When the train is on the road, it moves with respect to the Earth at a speed of 35 km / h. When we arrive at the station we change the reference system from the ground to the boy who is in the station, therefore the speed of the train can change
v ’= v + u
where v is the speed of the train with respect to the boy, v is the speed with respect to the ground and u the speed of the boy with respect to the ground
In general, the people in the station are still, that is, their speed with respect to the ground is zero, consequently the speed of the train does not change.
The correct answer is that the train is moving relative to the boy.
A dog wishes to swim across a slow moving stream. The current velocity is 3.0m/s. The distance directly across the stream is 50m. If the dog point himself directly across the stream, it will take .....
Answer:
Time = 16.667 seconds
Explanation:
Given the following data;
Distance = 50 meters
Velocity = 3 m/s
To find the time it will take;
Velocity can be defined as the rate of change in displacement (distance) with time. Velocity is a vector quantity and as such it has both magnitude and direction.
Mathematically, velocity is given by the equation;
Velocity = distance/time
Making time the subject of formula, we have;
Time = distance/velocity
Time = 50/3
Time = 16.667 seconds
Define measurement with examples.
Explanation:
Measurement is defined as the act of measuring or the size of something. An example of measurement means the use of a ruler to determine the length of a piece of paper. An example of measurement is 15" by 25". ... The dimension, quantity, or capacity determined by measuring.
Measurement refers to the comparison of unknown physical quantity with a known quantity.
for eg. measurement of body while sewing clothes.......
20. A semiconductor is a
crystalline solid that conducts current under any condition
metallic solid that conducts current under any condition
metallic solid that conducts current under certain conditions
crystalline solid that conducts current under certain conditions
Answer:
D. crystalline solid that conducts current under certain conditions
Explanation:
Semiconductors are crystalline solids that has the ability to conduct electrical currents but on certain conditions e.g heat. The conduction of semiconductors is less than that of conductors (metals) but more than insulators (nonmetals), hence, they are said to be intermediates of conductors and insulators in terms of electrical conductivity.
Examples of semiconductors are silicon, boron, carbon, germanium, arsenic etc.
Las carreras de velocidad pura en el atletismo son:
A. Un ladrón perseguido por la policia
B.100 y 200 mts planos
C. salir corriendo cuando la mama lo va a castigar
D.N.A
Which element does not have the same number of electrons in its outermost shell as the other elements in its group?(1 point)
hydrogen (H)
bromine (Br)
boron (B)
helium (He)
Answer:
The answer is helium (He)
Explanation:
Because helium is in the group 18, and the other elements of group 18 have 8 electrons in it's outermost, while helium just have 2 electrons
Helium (He) does not have the same number of valence electrons as other elements in its group.
The periodic table is divided into groups with the last number of the group coinciding with the number of electrons that an element in the group has in its outermost or valence shell.
Helium is in group 18 which means that it should have the same number of valence electrons as :
NeonArgonKryptonXenon and,RadonYet Helium only has 2 valence electrons. We can therefore conclusively say that Helium does not have the same number of valence electrons as other elements in its group.
More information is available at https://brainly.com/question/20944279.
It is easier to lift the same load by using three pulley system than by using two-pulley system. why give reason.
Logic behind is lies behind the mechanical advantage of the provided bt the Pulley system.
as if we calculate the mechanical advantage of the 2 Pulley system we will have the value 2
And if we will calculate the mechanical advantage of the 3 pulley system then we will get the value of 3
so due to extra mechanical advantage we feel it easy to move with 3 pulley system then 2 Pulley system
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After landing the aeroplane's momentum becomes zero. Explain how
the law of conservation holds here.
Answer:
The law of momentum conservation can be stated as follows. For a collision occurring between object 1 and object 2 in an isolated system, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision.
Why is it difficult to maintain constant speed of a vehicle?
Answer:
The road surface is always rough, so the frictional force between the tires and the road surface make it difficult to maintain constant speed because acceleration always changes.
IA body starts to move from rest and travels with uniform acceleration of 7mls2. How far will the body move in 4 second .
Please help it's for a test.
A car of mass 1000kg is traveling 30m/s
a) What is the kinetic energy?
b) How high will it have to travel up a hill to have the same potential as kinetic energy as this speed? Remember Ep-Ek
Answer:
Explanation:
[tex]KE=\frac{1}{2}mv^2[/tex] so filling in:
[tex]KE=\frac{1}{2}(1000)(30)^2[/tex] so to 2 sig figs (which is actually not accurate, but oh well...)
KE = 450000 J
If we want to find out how high it will have to travel up a hill so that its PE is the same as the KE at this speed, we set the value for KE = to PE:
450000 = (1000)(9.8)h so
[tex]h=\frac{450000}{(1000)(9.8)}=45.9m[/tex]
The gravitational force of the two objects is 6.67x10-11N. Explain this statement.
Answer:
it means that the force of attraction between two object in gravitation is 6.67×10-11N
It means that the force of attraction between two object in gravitation is 6.67×10-11N.
What is the formula of mass in gravitational force?The formula is g = GM/r2, Where M is the mass of the Earth, r is the radius of the Earth (or distance between the center of the Earth and you, standing on its surface), and G is the gravitational constant. G (without the subscripts) is the gravitational constant, and c is the speed of light.
What is the gravitational force between two objects?The gravitational force between two objects is proportional to their masses and inversely proportional to the square of the distance between their centers. joining the two centers of masses.
Learn more about gravitational force here: brainly.com/question/13010127
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Una partícula efectúa un MAS cuya ecuación es: x=0,3 cos (2t + /6) m. Determinar: Amplitud, frecuencia angular, fase inicial, periodo, frecuencia de oscilación y posición en t=0,25 s
Answer:
The answer is below
Explanation:
Una partícula efectúa un MAS cuya ecuación es: x=0.3cos (2t + π/6) m. Determinar: Amplitud, frecuencia angular, fase inicial, periodo, frecuencia de oscilación y posición en t=0.25 s
Solution:
La ecuación de la onda es:
x = A cos (ω t + Ф), donde:
A = amplitud, ω = frecuencia angular = 2 π / T = 2 π f, Ф = fase inicial, f = frecuencia, T = período
Por lo tanto, comparando la ecuación de la onda con x = 0.3cos (2t + π / 6), obtenemos:
a) A = 0.3
b) ω = 2 rad / s
c) Ф = π / 6 rad
d) ω = 2π / T
2 = 2π / T
T = 3.14 s
e) ω = 2πf
2 = 2πf
f = 0.32 Hz
f) en t = 0.25 s:
x (t) = 0.3cos (2 * 0.25 + π / 6) = 0.22 m
4. An aluminium bar weighs 17 kg in air. How much force is required
to lift the bar while it is immersed in gasoline? The density
of aluminium is 170 kg/m' and that of gasoline is 42 kg/m
Explanation:
1ml = 2.7g
Xml = 1.5g
Divide 1.5 by 2.7 to find X.
Obviously, since 1.5 is less than 2.7, you know the answer will be less than 1.
(it’s .5555555555)
state any two effects of gravitational force
Answer:
The effect of gravity extends from each object out into space in all directions, and for an infinite distance. However, the strength of the gravitational force reduces quickly with distance. Humans are never aware of the Sun's gravity pulling them because the pull is so small at the distance between the Earth and Sun.
Answer:
The Earth's gravitational force accelerates objects when they fall. It constantly pulls, and the objects constantly speed up.
Explanation:
What is the size of the force acting on a copper wire with a magnetic flux density of 3.6 x 10-2 T acting at
right angles to the wire of length 24 m and current of C:048 A? Give your answer to an appropriate
number of significant figures.
Answer:
F = 0.414 N
Explanation:
Given that,
Magnetic flux density,[tex]B=3.6\times 10^{-2}\ T[/tex]
The length of the wire, l = 24 m
Current, I = 0.48 A
We need to find the force acting on the wire. The formula for the force is given by:
[tex]F=ILB[/tex]
Put all the values,
[tex]F=0.48\times 24\times 3.6\times 10^{-2}\\\\F=0.414\ N[/tex]
So, the force acting on the copper wire is equal to 0.414 N.
The magnetic force of the copper wire is 41.472 N.
Magnetic force of the copper wire
The magnetic force of the copper wire is calculated by applying the following equation.
F = BIL x sinθ
Where;
θ is the inclination of the magnetic fieldI is the currentL is the length of the wireB is the magnetic field strength = flux densityF = (3.6 x 10⁻²) x (48) x 24 x sin(90)
F = 41.472 N
Thus, the magnetic force of the copper wire is 41.472 N.
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When applying an arm sling, the injured arm's hand should be placed in a ________ position in the sling, and above the level of the elbow.
Answer:
The answer is "thumb-up".
Explanation:
The sling often called the arm sling, is a solution for preventing either shoulder or elbow motion during healing. A triangle bandage could be constructed.
A sling is a strong tissue loop that descends from the head to hold the forearm. The armrests in the sling bent also at the elbow.
The injured hand of the forearm should be positioned inside the pin position in the joint above the level of the elbow when putting the forearm sling.
A boy is moving a stone in a horizontal circle by mean of a thread attached to ut. The length if the threads us 1 m and the weight of the stone is 0.02 kg . The maximum tension of the thread can withstand us 1 ×10 ^-4 N. The boy is gradually increasing the speed if rotation. At what speed if the stone does the thread break ?
Answer:
Explanation:
This is a centripetal force problem where tension supplies the centripetal force needed to keep the stone moving in a circular manner. That formula for that is
[tex]F_c=T=\frac{mv^2}{r}[/tex] and filling in what we know:
[tex]1*10^{-4}=\frac{.02v^2}{1}[/tex] and solve that for v:
[tex]v=\sqrt{\frac{1*10^{-4}}{.02} }[/tex] which gives us a velocity of .07 m/s. Anything greater than this will break the string.
Compare the vertical and horizontal components of velocity for a ball launched at an angle on a level surface. How do the vertical and horizontal components of the ball's velocities change as it travels through the air?
Answer:
horizontal velocity remaing constan thorough out the motion but the vertical motion's velocity changes due to the gravity acting on it.
for everl 1 second the velocity decreases by 9.8 that is the gravity
Which statement is the best interpretation of the ray diagram shown?
Answer:
Explanation:
First off, this lens is concave. Second, the image is obviously smaller, and third, the only thing that is NOT obvious, is the fact that real images are always upside down and virtual images are always right-side-up. So the choice you're looking for is D.
Answer:
D - A concave lens forms a smaller, virtual image
Explanation:
Which contributions did Galileo make to the model of the solar system? Select two options.a mathematical model for the orbits of the planetsscientifically accurate data on planetary orbitsdata that showed that planets reflected sunlight similar to Earth’s moonthe idea that stars are other suns that do not moveobservations of the moons of Jupiter rotating around the gas giant
Answer:
Data that showed that planets reflected sunlight similar to Earth's moon
Observations of the moons of Jupiter rotating around the gas giant
Explanation:
Two of Galileo's contributions to the model of the solar system which he was able to observe with the aid of a early version of the modern telescope which he built himself, following the invention of the 'spyglass' are;
1) The phases of Venus motion round the Sun which is similar to the motion of the moon round the Earth that showed that planets in orbit of the Sun reflected sunlight like the Moon
2) The four moons that rotate around Jupiter.
Answer:
it C and E or 3 and 5
Explanation:
by how much is the weight of body less on the moon surface than on earth surface why
Answer:
Our weight on moon is less than it would be on Earth.
Explanation:
Due to a difference of the strength of gravity on the moon. The moon's gravitation force is determined by the mass and the size of the moon. Since the moon has significantly less mass than the Earth, it will not pull objects toward itself at the strength that Earth will. This means that if you went to the moon you would weigh less, even though your mass stays the same.
A baseball pitcher throws a 0.14 kg ball toward a batter who is 18 m away.
The ball is traveling at 40 m/s when it leaves the pitcher's hand. What is the
ball's kinetic energy at this point?
A. 112 J
OB. 224 J
C. 12J
D. 3 J
SUBMIT
Answer:
A. 112 J
Explanation:
KE = ½mv² = ½(0.14)40² = 112 J
A girl walks 55 m downhill in 3.2 s. What is her average velocity?
Answer:
V = 17.2
Explanation:
Speed = distance(m) / time(s)
= 55m / 3.2s
=17.2 m/s
1. 20kg of water is ejected horizontally in 10s; the speed of the water leaving the nozzle is 30m/s. Calculate the force experienced by a fire-fighter holding the hose.
Answer 60 NEWTON
Explanation:
FORCE = MASS * acceleration
acceleration= VELOCITY / TIME
acceleration= 30 / 10 = 3 M/S2
FORCE = MASS * acceleration
FORCE = 20 *3 = 60 NEWTON
A hot air balloon is ascending at the rate of 1.2m/s and is 80m above the ground when a package is dropped over the side.
1) How long does the package take to reach the ground?
2) With what speed does it hit the ground?
Answer:
The package reaches the ground in
4.67 s
and hits the ground with a speed of
33.8 m/s
.
Explanation:
Noticing large amounts of algal growth in her small farm pond, a farmer adds about 20 grass carp to feed on the abundant algae and plants. After several years, the carp grow large, exceeding 20 pounds each in size. Late one summer, the farmer notices that the carp and most of the other fish are dead. The water also smells very bad. Which one of the following is the most likely explanation for the death of these fish?
A. the algae overgrew the pond and produced toxic levels of ozone
B. carbon dioxide released by the carp and algae eventually suffocated the fish in the pond
C. the large carp grew so large that they could not get enough oxygen
D. bacteria feeding on the large volume of carp feces depleted the oxygen
Answer:
D. bacteria feeding on the large volume of carp feces depleted the oxygen
Explanation:
In the context, it is given that in a small farm pond, the owner added 20 grass carp and feed them with the abundant plants and algae that is found on her pond. The carp grew large after many years but one summer the owner found the grass carps along with other fishes were dead.
The most possible explanation for the dead of the fishes in the pond because the bacteria feeds on the carp feces which depletes the dissolved oxygen present in the water. Thus the fishes could not breathe and were finally dead.
Therefore, the correct option is (D).
the mass of an object is 45 kg and it has a density of 5 gram per centimetre cube what is the volume
Density = Mass/Volume
=> 5g/cm³ = 45kg/Volume
=> 0.005kg/cm³ = 45kg/Volume
=> Volume = (cm³×45kg)/0.005kg
=> Volume = 9000kg/cm³
5 grams fits into 45 kg 9,000 times.
Since each 5 grams occupies 1 cm³, 9,000 little packages of 5 grams must occupy 9,000 cm³ . (That's 9 liters.)
Two rams run toward each other. One ram has a mass of 44 kg and runs south with a speed of 6 m/s, while the other has a mass of 50 kg and runs north with a speed of 3 m/s. What will the momentum of the system made up of the two rams be after they collide? Assume the total momentum of the system is conserved.
A. 114 kg-m/s south
B. 414 kg-m/s south
C. 414 kg m/s north
D. 114 kg-m/s north
A ball is thrown vertically upward. As it rises, what happens to its potential energy?
Answer:
Explanation:
As the ball rises, its PE increases because the potential energy is equal to the mass of the ball times gravity times the height of the ball. The higher the height, the higher the PE.
Answer:
According to the law of conservation of energy its kinetic energy is getting converted in to potential energy because of gain in height. So, if the velocity of a ball goes on decreasing when it is thrown vertically upwards. When its velocity becomes zero, its potential energy becomes maximum.
