a.
[2]
A train covers 450 km in 5 hr. between Station A and Station B.
What is the average speed of train in km/h and m/s.

Answers

Answer 1

Answer:

90 km/h

50 m/s

Explanation:

Distance = 450 km

Time = 5hrs

Speed = Distance/Time

450/5 = 90 km/h

1 km = 1,000 m

1 hr = 60m = 60 x 60 = 3,600 sec

but since it's 5hrs = 60 x 300m = 18,000

90 x 1,000 = 90,000/18,000 = 50 m/s


Related Questions

why physics ought to be studied?​

Answers

Answer:

The goal of physics is to understand how things work from first principles. ... Courses in physics reveal the mathematical beauty of the universe at scales ranging from subatomic to cosmological. Studying physics strengthens quantitative reasoning and problem solving skills that are valuable in areas beyond physics.

Một con lắc là xo treo thẳng đứng có độ cứng 30 N/m và vật nặng có khối lượng 320 g. Kích thích dễ cho quá nặng dao động điều hoà theo phương thẳng đứng xung quanh vị trí cân bằng với biên độ 6 cm. Lấy g = 10m/s. Độ lớn lực kéo lớn nhất của là xa liễn điểm treo trong quá trình quả nặng dao động là

Answers

Answer:

The maximum force is 1.8 N.

Explanation:

A pendulum is a vertically hanging spring with a stiffness of 30 N/m and a mass of 320 g. The excitable excitation oscillates vertically around the equilibrium position with an amplitude of 6 cm. Take g = 10m/s. The magnitude of the maximum pulling force of the distance from the suspension point during the oscillation of the weight is

stiffness, K = 30 n/m

mass, m = 320 g

amplitude, A = 6 cm = 0.06 m

g = 10 m/s^2

Let the maximum acceleration is a.

[tex]a = w^2 A\\\\a = \frac{K}{m}A\\\\Force, F = m a \\\\F = K A\\\\F = 30 \times 0.06 \\\\F = 1.8 N[/tex]

Describe the advantages and disadvantage is of living in a floodplain

Answers

Answer:

:) :::::::::::::::::::::::::::::::))))

What's Alpha beta gamma emission??

Answers

Alpha radiation is the name for the emission of an alpha particle in fact an helium nuclei, beta radiation is the emission of electrons or positrons , and gamma radiation is the term used for the emission of energetic photons.

How would you find the resistance of a parallel circuit with n identical resistors?

Answers

9514 1404 393

Answer:

  R/n

Explanation:

For a given voltage V across each resistor R, the current is V/R. Since there are n parallel paths, the total current is n(V/R). The effective resistance is ...

  Reff = V/I = V/(nV/R)

  Reff = R/n

An image of a car with height of 14 cm occurred in the mirror which is located at a T-
intersection. If the car height is 140 cm and the radius of the curvature of the mirror is 60 cm,
how far is the car from the mirror?
helpp me!!!!!!

Answers

Answer:

The distance of car form the mirror is 330 cm.

Explanation:

height of object, h = 140 cm

height of image, h' = 14 cm

radius of curvature, R = 60 cm

focal length, f = R/2 = + 30 cm

Let the distance of image is v and the distance of object is u.

[tex]\frac{h'}{h}\frac{v}{u}\\\\\frac{14}{140} =\frac{v}{u}\\\\v =\frac{u}{10}[/tex]

Use the formula of focal length

[tex]\frac{1}{f}=\frac{1}{v}+\frac{1}{u}\\\\\frac{1}{30}=\frac{10}{u}+\frac{1}{u}\\\\\frac{1}{30}=\frac{11}{u}\\\\u = 330 cm[/tex]

A blue line with 5 orange tick marks then one red tick mark then 4 orange tick marks. The number zero is above the red tick mark.Assume each tick mark represents 1 cm.Calculate the total displacement from 0 if an object moves 3 cm to the left, then 7 cm to the right, and then 6 cm to the left.The object moves cm to the left.What is the total distance the object travels? cm

Answers

Answer:

16 cm

Explanation:

Given that,

The object begins from 0 and moves 3cm towards left side followed by 7 cm towards the right and then, 6 cm towards the left side.

Let the x-axis to be the +ve and on the right side and -ve on the left

Thus, displacement would be:

= 0 -3 + 7 -6

= -2 cm

This implies that the object displaces 2cm towards the left.

While the total distance covered by the object equal to,

= 0cm + 3cm + 7cm + 6cm

= 16 cm

Thus, 16 cm is the total distance.

Answer:

Its 2 to the right

Explanation:

edge :p

If the mass of the Jupiter is 1.9*10 kg and radius is fbx loom what is acclerallon due to gravity on the supiter ?​

Answers

Answer:

[tex]g=25.92\ m/s^2[/tex]

Explanation:

Given that,

The mass of the Jupiter,[tex]M=1.9\times 10^{27}\ kg[/tex]

The radius of Jupiter,[tex]r=69,911\ km=69911\times 10^3 km[/tex]

We need to find the acceleration due to gravity on Jupiter. The formula is

[tex]g=G\dfrac{M}{r^2}[/tex]

Put all the values,

[tex]g=6.67\times 10^{-11}\times \dfrac{1.9\times 10^{27}}{(69911\times 10^3)^2}\\\\g=25.92\ m/s^2[/tex]

So, the value of acceleration due to gravity on the Jupiter is [tex]25.92\ m/s^2[/tex].

what is the effect of pressure on boiling and melting substance?

Answers

Answer:

The boiling point of liquids always increases when pressure is applied on a liquid. This is because the molecules of a liquid will need more energy to turn into a gaseous state when pressure is applied on that substance.

A car moves 20 km towards the North and then 35 km at an angle of 60o towards west of North. Its magnitude of displacement from the initial position will be

Answers

Answer:

15

Explanation:

displacement = initial position - final position

Jennifer has a credit score of 450. Her bank recently approved her for a credit card. What will her interest rate be?
A. High, as her credit score is low, indicating that she is a high risk borrower
B. Low as her credit score is good
C. Big as her credit score is good
D. Low as she is a high risk borrower

Answers

Answer:

A

Explanation:

low credit score means its more risky to lend someone money

If the density of a substance is 5g/cm3 and the volume is 10cm3,
determine the mass.

Answers

Answer:

(5g/cm³)*(10cm³) = 50g

Explanation:

This is just a conversion formula. Easy to find using dimensional analysis.

(5g/cm³)*(10cm³) = 50g

Answer:

[tex]\boxed {\boxed {\sf 50 \ grams}}[/tex]

Explanation:

Density is the amount of mass per unit volume, so the formula is:

[tex]d = \frac{m}{v}[/tex]

The density of the substance is 5 grams per cubic centimeter and the volume is 10 cubic centimeters.

d= 5 g/cm³ v= 10 cm³

Substitute the values into the formula.

[tex]5 g/cm^3 = \frac{m}{10 \ cm^3}[/tex]

We are solving for the mass, so we have to isolate the variable m. It is being divided by 10 cubic centimeters. The inverse of division is multiplication, so we multiply both sides of the equation by 10 cm³.

[tex]10 \ cm^3 *5 g/cm^3 = \frac{m}{10 \ cm^3} * 10 \ cm^3[/tex]

[tex]10 \ cm^3 *5 g/cm^3 = m[/tex]

The units of cubic centimeters (cm³) cancel.

[tex]10 *5 g = m[/tex]

[tex]50 \ g=m[/tex]

The mass of the substance is 50 grams.

Can someone pleassse help me

Answers

Answer:

ysss

datvklgfvj

tdgjbc

why solid keep their shape?

Answers

Answer:

Solids can hold their shape because their molecules are tightly packed together. ... Atoms and molecules in liquids and gases are bouncing and floating around, free to move where they want. The molecules in a solid are stuck in a specific structure or arrangement of atoms

Hope this helps ☆*:. o(≧▽≦)o .:*☆

A small emergency generator supplies 432 000 000 J of electrical energy in twenty-four hours. What is the average power output of the generator?

Answers

Answer:

P = 5 kW

Explanation:

Given that,

Electrical energy = 432 000 000 J

Time, t = 24 h = 86400 s

We need to find the power output of the generator. We know that,

Power = work done/time

So,

[tex]P=\dfrac{432 000 000}{86400}\\\\P=5000\ W[/tex]

or

P = 5 kW

So, the power output of the generator is 5 kW.

Cual es el deporte que le da fortaleza y flexibilidad al cuerpo

Answers

Answer:

Aesthetic sports

Explanation:

Aesthetic sports are the one's that need well-developed physical qualities such as strength, agility, stamina, flexibility, and technical knowledge and artistry, in addition to technical ability and artistry. Elite athletes in these sports generally have a low abdominal fat , and the ranking is subjective.

In aesthetic sports like gymnastics, swimming, and figure skaters, dynamic and proactive flexibility is required.

The primary circuit of a transformer has a voltage of 80 V and 300 windings. The secondary circuit has a voltage of 240. How many windings are there in the secondary circuit? *

Answers

Answer:

900 windings

Explanation:

Applying,

Vs/Vp = Ns/Np............. Equation 1

Where Vs = Secondary voltage, Vp = primary voltage, Ns = Number of turns in the secondary circuit, Np = number of turns in the primary circuit

make Ns the subject of the equation

Ns = VsNp/Vp........... Equation 2

From the question,

Given: Vs = 240 V, Np = 300 windings, Vp  = 80 V

Substitute these values into equation 2

Ns = (240×300)/80

Ns = 900 windings

what mean by expansion effect of heat

Answers

Answer:

Explanation:

-Cambio de temperatura

Al calentar un cuerpo la temperatura aumenta

Es el efecto más inmediato del calor, el aumento de la temperatura. Al calentar un cuerpo, es habitual, aunque no siempre, que el cuerpo aumente de temperatura. El aumento dependerá de la cantidad de calor que se suministra, del tipo de sustancia y de su cantidad.

-Dilatación

Cuando un objeto se calienta, su volumen aumenta. Este fenómeno se llama dilatación térmica. Por el contrario, cuando un objeto se enfría, su volumen disminuye, debido a la contracción térmica.

Cuando se calienta un cuerpo, además de cambiar de estado o variar su temperatura, también cambia su tamaño, se dilata.

Por ejemplo, los puentes no se construyen de una única pieza, sino que suelen presentar uno o varios cortes longitudinales, las llamadas juntas de dilatación. Si no existieran esas juntas, los cambios de longitud del puente entre el invierno y el verano o entre el día y la noche acabarían por romperlo.

La dilatación de un cuerpo dependerá del aumento de temperatura que experimente, de su tamaño y de la sustancia de que esté hecho. Cuanto más aumente la temperatura más aumentará su tamaño, lo mismo que cuanto mayor sea, mayor se hará.

Todos los cuerpos, ya sean sólidos, líquidos o gaseosos, varían su tamaño cuando intercambian calor con otro cuerpo.

-Cambios de estado:

Si una sustancia modifica el estado de sólido, líquido o gaseoso, se produce un cambio de estado. Un cambio de estado es una modificación en la forma en que se disponen las partículas que constituyen una sustancia.

El estado en que se encuentre un cuerpo depende de la presión a la que está sometido y de su temperatura. Para cambiar su estado se debe modificar alguna de estas variables, o ambas. Al elevar la temperatura de una sustancia sólida, aumenta la agitación de sus partículas.

Answer:

All forms of matter (solid, liquid and gas) undergo expansion on heating. When a solid is heated, the atoms gain energy and vibrate more vigorously. This results in the expansion of the solid. For a given change in temperature, the extent of expansion is smaller in solids than in liquids and gases. This is due to the rigid nature of solids.

Explanation:

UNA MASA DE 0,5 KG ESTA SOBRE UNA PENDIENTE SUJETA MEDIANTE UNA CUERDA QUE IMPIDE UN DESLICE. ¿QUE FUERZA HACE LA CUERDA?

Answers

Answer:

Tension force acts along the inclined plane.

Explanation:

A MASS OF 0.5 KG IS ON A SLOPE FASTENED BY A ROPE THAT PREVENTS SLIDING. WHAT FORCE DOES THE ROPE MAKE?

A mass of 0.5 kg is fastened on a slope. So there are the two components of weight.  

m g sin A acts along the plane in the downwards direction.

m g cos A acts perpendicular to the plane in upwards direction.

The force which acts of the rope as the mass is fastened is the tension force on the rope.

So, the tension force is there.

To make a position-time graph, you plot position relative to the starting point on the y-axis against the corresponding_______on the x-axis

Answers

Answer:

time.

Explanation:

Motion can be defined as a change in the location (position) of a physical object or body with respect to a reference point.

This ultimately implies that, motion would occur as a result of a change in location (position) of an object with respect to a reference point or frame of reference i.e where it was standing before the effect of an external force.

A reference point refers to a location or physical object from which the motion (movement) of another physical object or body can be determined.

Mathematically, the motion of an object is described in terms of acceleration, time, distance, speed, velocity, position, displacement, etc.

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.

A position-time (x-t) graph is a graph of the position of an object against (versus) time.

To make a position-time graph, you should plot the values of the position of an object or body with respect to the starting point on the y-axis against the corresponding time on the x-axis.

Generally, the slope of the line of a position-time (x-t) graph is typically used to determine or calculate the velocity of an object.

An instantaneous velocity can be defined as the rate of change in position of an object in motion for a short-specified interval of time. Thus, an instantaneous velocity is a quantity that can be found by measuring the slope of a line that is tangent to a point on the graph.

In conclusion, the x - t graph also referred to as the position-time graph is used for determining the instantaneous velocity from the slope.

is the answer correct or wrong ​

Answers

Answer:

wrong answer because m=100

Explanation:

I think it is incorrect

Ah, I tried

A basketball is shot by a player at a height of 2.0 m. The initial angle
was 53° above horizontal. At the highest point the ball was travelling 6
m/s. If he scored (the ball went through the rim that is 3.00 m above the
ground), what was the player’s horizontal distance from the basket?

Answers

Answer:

The answer is "8.28 m".

Explanation:  

[tex]\to u \cos 53^{\circ}=6 \ \text{therefore the horizontal velocity is constant alaways}\\\\\therefore[/tex]

[tex]u= \frac{6 \times 5}{3}= \frac{30}{3}= 10\ \frac{m}{s}\\\\[/tex]

In the projectfile when vertical displacement is 1 then 5 m comes at farther sides

Using  

[tex]S=ut-\frac{1}{2} gt^2\\\\1=u\sin 53^{\circ}\times t-5t^2\\\\1=8t-5t^2\\\\5t^2-8t+1=0\\\\ t=\frac{8\pm \sqrt{64-20}}{10} \\\\=\frac{8\pm 2\sqrt{11}}{10} \\\\t_2=\frac{8+2\sqrt{11}}{10} \\\\[/tex]

[tex]Distance=u \cos 53^{\circ}\times t_2\\\\[/tex]

               [tex]=6 \times \frac{8\pm 2\sqrt{11}}{10} \\\\=\frac{24\pm 6\sqrt{11}}{5} \\\\= 8.28 \ m[/tex]

A student wishes to find the average thickness . she obtain the following measurements
mass of sheet = 60.7g
lenght of sheet = 50.0cm
width of sheet = 30.0 cm
calculate the student's values for
(i) the volume of the sheet
( ii) the average thickness of the sheet

Answers

Complete Question:

The density of aluminium is 2.70g/cm³. The thickness of a rectangular sheet of aluminium foil varies, but is much less than 1 mm.

A student wishes to find the average thickness. She obtain the following measurements

Mass of sheet = 60.7g

Length of sheet = 50.0cm

Width of sheet = 30.0 cm

Calculate the student's values for

(i) the volume of the sheet

(ii) the average thickness of the sheet

Answer:

Thickness = 0.015 cm

Explanation:

Given the following data;

Mass of sheet = 60.7gLength of sheet = 50.0cmWidth of sheet = 30.0 cmDensity = 2.70g/cm³

I. To find the volume of the sheet;

Density can be defined as mass all over the volume of an object.

Simply stated, density is mass per unit volume of an object.

Mathematically, density is given by the formula;

[tex] Density = \frac {mass}{volume} [/tex]

Making volume the subject of formula, we have;

[tex] Volume = \frac {mass}{density} [/tex]

Substituting into the formula, we have;

[tex] Volume = \frac {60.7}{2.70} [/tex]

Volume = 22.48 cm³

II. Volume = length * width * height

But, height = thickness

Volume = length * width * thickness

22.48 = 50 * 30 * thickness

22.48 = 1500 * thickness

[tex] Thickness = \frac {22.48}{1500} [/tex]

Thickness = 0.015 cm

Conversion:

1 mm = 0.1 cm

X mm = 0.015 cm

X = 0.015/0.1 = 0.15 mm

Therefore, the thickness of the rectangular sheet of aluminium foil is less than 1 millimetre.

I don't know how to answer this question, can someone pls help?
- Explain how a wave can transmit energy to a medium without transporting matter.

Thank you for your time!

Answers

Answer:

Consider the energy the earth receives from the sun. The electromagnetic waves travel thru empty space until they interact with some medium surrounding the earth: ozone, atmosphere, solids, etc.

This is contrasted to longitudinal waves such as sound waves which can only travel thru the medium with which they interact.

A wire, 20m long, is heated from a temperature of 5°C to 55°C. If the change in length is 0.020m, calculate the linear expansivity of the wire.​

Answers

Answer:

0.01998⁰C;¹

Explanation:

you can see all steps in photo

When 100.0 mL of ethyl alcohol is heated from 10.0 C to 35.0 C, about how much thermal energy
is absorbed by the ethyl alcohol? (Assume the density of ethyl alcohol to be 0.790 g/mL.)

Answers

Answer:

Q = 194.34  J

Explanation:

Given that,

100.0 mL of ethyl alcohol is heated from 10.0 C to 35.0 C.

We need to find the amount of thermal energy  absorbed by the ethyl alcohol.

The density of ethyl alcohol is 0.790 g/mL.

The formula for heat absorbed is given by :

[tex]Q=mc\Delta T\\\\As, d=\dfrac{m}{V}\\\\So,\\Q=dVc\Delta T\\\\Q=0.79\times 100\times 2.46\\\\Q=194.34\ J[/tex]

So, 194.34  J of thermal energy is absorbed by the ethyl alcohol.

A bullet from a gun at 30° to the horizontal remains in flight for 25s before touching the ground.Calculate the velocity of the projection.​

Answers

Answer: The velocity of the bullet will be more than half of its earlier velocity

Explanation: I did it on a test and it was right because i calculated 30 degrees within 25 seconds and it was half times the velocity

i hope this helps sorry if i got it wrong

2. A cinder block is sitting on a platform 20 m high. It weighs 16kg. The block has
_ joules of potential energy.

Answers

Answer:

3136 Joules

Explanation:

Applying,

P.E = mgh.............. Equation 1

Where P.E = potential energy, m = mass of the cinder block, h = height of the platform, g = acceleration due to gravity.

From the question,

Given: m = 16 kg, h = 20 m

Constant: g = 9.8 m/s²

Substitute these values into equation 1

P.E = 16(20)(9.8)

P.E = 3136 Joules

Hence the potential energy of the cinder block is 3136 Joules

A mother is pulling a sled at constant velocity by means of a rope at 37°. The tension on the rope is 120 N. Mass of children plus sled is 55 kg. The mother has a mass of 61 kg.
a) Draw FBD for the sled with the kids as one object
b) Draw FBD for the mother
c) Find the normal force on the sled and on the mother
d) Find the kinetic friction acting on the sled and the static friction acting on the mother
e) Find the coefficient of kinetic friction for the sled

Answers

Answer:

Please find the complete solution in the attached file.

Explanation:

1. Determine the magnitude of two equal but opposite charges if they attract one another with a force of 0.7N when at distance of 0.3m apart in a vacuum.​

Answers

Answer:

q = 2.65 10⁻⁶ C

Explanation:

For this exercise we use Coulomb's law

        F =[tex]k \frac{q_1q_2}{r^2}[/tex]

In this case they indicate that the load is of equal magnitude

       q₁ = q₂ = q

the force is attractive because the signs of the charges are opposite

       F = [tex]k \ \frac{q^2}{r^2}[/tex]

       q = [tex]\sqrt{\frac{F \ r^2}{k} }[/tex]

we calculate

        q = [tex]\sqrt{\frac{0.7 \ 0.3^2 }{9 \ 10^9} }[/tex]

        q = [tex]\sqrt{7 \ 10^{-12} }[/tex]Ra 7 10-12

        q = 2.65 10⁻⁶ C

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