Answer:
57
Explanation:
a boat ended up with a velocity of 30.m/s [N30.E] after it experienced an acceleration of 3.0m/s^2 [S] for a period of 4.0s what displacement did the boat cover
Answer:
96 m
Explanation:
The average velocity over those 4 seconds is the velocity after 2 seconds:
30 m/s -(2 s)(3.0 m/s^2) = 24 m/s
The displacement is the product of this average velocity and the duration of the acceleration:
d = (24 m/s)(4 s) = 96 m
The boat covered 96 m while being accelerated.
Highlight two factors which shows that heat from the sun does not reach the earth surface by convection
Answer:
Explanation:
The heat from the Sun gets to the surface of the Earth by radiation and not by convection because:
i. Radiation does not require material medium for its propagation: Since the space between the Sun and Earth is a vacuum ( i.e it is an empty space), then the only method for the heat from to Sun to get to the Earth is by radiation. This method does not require a material medium, while convection is a method that requires material medium for its propagation.
ii. Radiation occurs without heating the intervening medium: During the propagation of the heat from the Sun to the Earth, the space between the two heavenly bodies is not heated up. Some fraction of the heat after hitting the surface of the Earth get reflected back into the Earth's atmosphere. While in convection, the medium would have been heated up in the process.
What type of sound do the thinner
strings on a guitar make?
A. Higher pitched sounds
B. Lower pitched sounds
C. Loud sounds
D. Quiet sounds
Answer:
d
Explanation:
I'm not perfectly sure so check again
Which of the following is true of highly conductive elements?
Answer:
A
Explanation:
i think a is the answer because if you take an example of group 1 and 2 metals on the periodic table you will notice that they are highly reactive but they have a few electrons in their outer most shells.
I hope this helps
(A) A triangular glass prism of thickness 12cm is placed on a mark on a piece of paper resting on a horizontal bench. If the refractive index of the material of the prism is 1.5, calculate the apparent displacement of the mark.
(B)Water is poured into a jar to a depth of 24cm. The bottom of the jar appears
to be raised by 6cm when viewed vertically. Calculate the refractive index of water.
Part A - The apparent displacement of the mark is 4 cm.
The refractive index of a material, n = real depth, D/apparent depth, L.
So, n = D/L
Since the refractive index of the triangular glass prism is 1.5, n = 1.5. Also, the triangular glass prism is 12 cm thick and placed on a mark on a piece of paper resting on a horizontal bench. So, the real depth of the mark on the piece of paper through the triangular prism is D = 12 cm and its apparent depth is L.
Since n = D/L,
making L, subject of the formula, we have
L = D/n
Substituting the values of the variables into the equation, we have
L = D/n
L = 12 cm/1.5
L = 8 cm
so, the apparent depth of the mark is 8 cm.
So, the apparent displacement of the mark is d = D - L = 12 cm - 8 cm = 4 cm
Thus the apparent displacement of the mark is 4 cm.
Part B - The refractive index of water, n = 1.33.
The refractive index of a material, n = real depth, D/apparent depth, L.
So, n = D/L
Since the depth of water in the jar is 24 cm, the real depth, D = 24 cm.
Also, the bottom of the jar appears to be raised by 6 cm. So, the apparent depth, L = 24 cm - 6 cm = 18 cm
Since n = D/L, the refractive index of water n = D/L
Substituting the values of the variables into the equation, we have
n = D/L
= 24 cm/18 cm
= 1.33
So, the refractive index of water, n = 1.33.
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the weight of a body is 420 newton.calculate it's mass
Answer:
42g
Explanation:
the mass of a body is given by
m=weight/gravity
=420/10
=42
I hope this helps
que tienen en común la materia y el sistema?
Answer:
La materia es la sustancia de la que está hecho todo material. En física, el sistema es una de las propiedades de la materia. Se puede transferir entre objetos y convertir en forma. No se puede crear ni destruir.
espero que te ayude!
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
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
Which is an example of current electricity?
Answer:
D
Explanation:
i just did it trust me
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
Which direction do electrons travel
A.from negative to positive
B.in either direction depending on the circuit
C.from positive to negative
D.they don’t move they simply exchange charge
Answer:
option a negative to positive
Explanation:
The flow of electrons is termed electron current. Electrons flow from the negative terminal to the positive. Conventional current or simply current, behaves as if positive charge carriers cause current flow. Conventional current flows from the positive terminal to the negative
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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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what's is acceleration. ?????
Answer:
Acceleration, rate at which velocity changes with time, in terms of both speed and direction. A point or an object moving in a straight line is accelerated if it speeds up or slows down. ... Acceleration is defined as the change in the velocity vector in a time interval, divided by the time interval.
Answer:
The rate of change in velocity with time A=finall velocity _intial velocity upon time
The energy required to change the state of a substance was determined to be E(H).
If the mass of the substance was DOUBLED, the value of E(H) will
(A) be halved
(B) be doubled
(C) be quadrupled
(D) remain constant
Answer:
ccccccccc or bbbbbbb or aaaaaaaa or ddddddd
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]
During what intervals was Jenny positively accelerating?
Answer:
3:00 - 3:02 and 3:07 - 3:08
Explanation:
Those are the only intervals in which Jenny's speed increased.
Answer and Explanation:
To know where Jenny was positively accelerating, we have to find where the slopes on the graph are increasing (in the positive direction).
By looking at the graph, we can see that at the intervals:
3:00 to 3:02 and 3:07 to 3:08
Jenny was positively accelerating, as there is an increase in speed during these time intervals.
#teamtrees #PAW (Plant And Water)
I hope this helps!
Which two statements are true about a system?
a)A system is a group of objects analyzed as one unit.
b)Energy that moves across system boundaries is conserved.
c)There’s only one way to define the boundaries of a system.
d)All systems are made by humans.
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
Bagaimanakah pelembapan bagi suatu sistem ayunan dapat diatasi dengan resonans?
Answer:
Those reaction in which one element replaces another element form its place is called Single displacement reaction
what is the relationship between electrostatic force and electric field?
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
When should a line graph be used?
A. When the independent variable is continuous and shows a causal link to the dependent variable.
B. When the independent variable is composed of categories and does not show a relationship.
C. When there is no independent variable.
D. When the independent variable is continuous and does not show a relationship to the dependent variable.
Answer:
A. When the independent variable is continuous and shows a causal link to the dependent variable.
Explanation:
A graph can be defined as the graphical representation of data (informations) on horizontal and vertical lines i.e x-axis and y-axis respectively.
In an experiment , the variable being manipulated by an experimenter is known as an independent variable while the dependent variable is the event expected to change when the independent variable is manipulated
Generally, a line graph should be used when the independent variable is continuous and shows a causal link to the dependent variable.
This ultimately implies that, a line graph should be used when the data changes continuously over time and as such there exist a linear relationship between the data (variables).
A person climbs out of swimming pool and stands in the open air.Explain why evaporation of water from the surface of the persons body causes the person to feel cold
Answer:
The person feels cool at first because the swimming pool water is usually cool and he/she has that water on his body. But when it evaporates, the cool air directly touches his body and that's why he/she feels cold.
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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 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)
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
in what condition does a body float
Answer:
if buoyant force is equal is equal to the weight of body then our body float. if density of our body is less than density of liqiud then our body float in water.
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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why a magnetic compass is used to determine the direction.
Answer:
the magnetic compass is used to determine direction because it is one of the most accurate form of magnet as we already know that a freely suspended magnet always faces towards north direction and south direction
