A train moving with a uniform speed covers a distance of 120 m in 2 s. Calculate

(i) The speed of the train

(ii) The time it will taketo cover 240 m.​

Answers

Answer 1

Answer:

(I)

[tex]{ \bf{s = ut + \frac{1}{2}a {t}^{2} }} \\ 120 = (u \times 2) + \frac{1}{2} \times 0 \times {2}^{2} \\ 120 = 2u \\ { \tt{speed = 60 \: {ms}^{ - 1} }}[/tex]

(ii)

[tex]{ \bf{s = ut + \frac{1}{2}a {t}^{2} }} \\ 240 = (60t) \\ { \tt{time = 4 \: seconds}}[/tex]


Related Questions

A uniform metre rule of mass 10g is balanced on a knife edge placed at 45cm mark. Calculate the distance of a mass 25g from the pivot​

Answers

Answer:

The distance of a mass 25g from the pivot​ is 18cm

Explanation:

Given

[tex]m_1 = 10g[/tex]

[tex]d_1 = 45cm[/tex]

[tex]m_2 = 25g[/tex]

Required

Distance of m2 from the pivot

To do this, we make use of:

[tex]m_1 * d_1 = m_2 * d_2[/tex] --- moments of the masses

So, we have:

[tex]10 * 45= 25* d_2[/tex]

[tex]450= 25* d_2[/tex]

Divide both sides by 25

[tex]18= d_2[/tex]

Hence:

[tex]d_2 = 18[/tex]

Magnets produce _________ in the spaces surrounding them

Answers

Answer:

magnetic field

Explanation:

A 2090-kg test rocket is launched vertically from the launch pad. Its fuel (of negligible mass) provides a thrust force so that its vertical velocity as a function of time is given by v(t) =At+Bt^2 , where A and B are constants and time is measured from the instant the fuel is ignited. The rocket has an upward acceleration of 1.50m/s 2 at the instant of ignition and, 1.00 s later, an upward velocity of 2.00 m/s. (a) Determine A and B , including their SI units. (b) At 4.00 s after fuel ignition, what is the acceleration of the rocket, and (c) what thrust force does the burning fuel exert on it, assuming no air resistance? Express the thrust in newtons and as a multiple of the rocket’s weight. (d) What was the initial thrust due to the fuel?

Answers

Answer:

a) A = 1.50 m / s²,  B = 1.33 m/s³,  b) a = 12.1667 m / s²,

c)  I = M (1.5 t + 1.333 t²) ,  d)  ΔI = M 2.833   N

Explanation:

In this exercise give the expression for the speed of the rocket

         v (t) = A t + B t²

and the initial conditions

         a = 1.50 m / s² for t = 0 s

         v = 2.00 m / s for t = 1.00 s

a) it is asked to determine the constants.

Let's look for acceleration with its definition

         a = [tex]\frac{dv}{dt}[/tex]

         a = A + 2B t

we apply the first condition t = 0 s

         a = A

         A = 1.50 m / s²

we apply the second condition t = 1.00 s

          v = 1.5 1 + B 1²

          2 = 1.5 + B

          B = 2 / 1.5

          B = 1.33 m/s³

the equation remains

           v = 1.50 t + 1.333 t²

b) the acceleration for t = 4.00 s

           a = 1.50 + 1.333 2t

           a = 1.50 + 2.666 4

           a = 12.1667 m / s²

c) The thrust

           I = ∫ F dt = p_f - p₀

           

Newton's second law

          F = M a

          F = M (1.5 + 2 1.333 t) dt

           

we replace and integrate

         I = M ∫ (1.5 + 2.666 t) dt

         I = 1.5 t + 2.666 t²/2

         I = M (1.5 t + 1.333 t²) + cte

in general the initial rockets with velocity v = 0 for t = 0, where we can calculate the constant

         cte = 0

         I = M (1.5 t + 1.333 t²)

d) the initial push

For this we must assume some small time interval, for example between

t = 0 s and t = 1 s

        ΔI = I_f - I₀

        ΔI = M (1.5 1 + 1.333 1²)

        ΔI = M 2.833   N

If you buy an amateur-sized reflecting telescope, say around 10 inches (25cm) aperture, it'll have something in it that sends the gathered starlight out the side of the telescope tube. What do we call this thing

Answers

Answer: objective lens

Explanation:

Light enters a refra

Light enters a telescope through a lens at the upper end, which focuses the light near the bottom of the telescope. An eyepiece then magnifies the image so that it can be viewed by the eye, or a detector like a photographic plate can be placed at the focus. The upper end of a reflecting telescope is open, and the light passes through to the mirror located at the bottom of the telescope. The mirror then focuses the light at the top end, where it can be detected. Alternatively, a second mirror may reflect the light to a position outside the telescope structure, where an observer can have easier access to it.

A wheel rotates about a fixed axis with an initial angular velocity of 13 rad/s. During a 8-s interval the angular velocity increases to 57 rad/s. Assume that the angular acceleration was constant during this time interval. How many revolutions does the wheel turn through during this time interval

Answers

Answer:

The number of revolutions is 44.6.

Explanation:

We can find the revolutions of the wheel with the following equation:

[tex]\theta = \omega_{0}t + \frac{1}{2}\alpha t^{2}[/tex]

Where:

[tex]\omega_{0}[/tex]: is the initial angular velocity = 13 rad/s              

t: is the time = 8 s

α: is the angular acceleration

We can find the angular acceleration with the initial and final angular velocities:

[tex] \omega_{f} = \omega_{0} + \alpha t [/tex]

Where:

[tex] \omega_{f} [/tex]: is the final angular velocity = 57 rad/s

[tex] \alpha = \frac{\omega_{f} - \omega_{0}}{t} = \frac{57 rad/s - 13 rad/s}{8 s} = 5.5 rad/s^{2} [/tex]

Hence, the number of revolutions is:

[tex] \theta = \omega_{0}t + \frac{1}{2}\alpha t^{2} = 13 rad/s*8 s + \frac{1}{2}*5.5 rad/s^{2}*(8 s)^{2} = 280 rad*\frac{1 rev}{2\pi rad} = 44.6 rev [/tex]

Therefore, the number of revolutions is 44.6.

       

I hope it helps you!

A pilot flies her route in two straight-line segments. The displacement vector A for the first segment has a magnitude of 243 km and a direction 30.0o north of east. The displacement vector for the second segment has a magnitude of 178 km and a direction due west. The resultant displacement vector is R = A + B and makes an angle ? with the direction due east. Using the component method, find (a) the magnitude of R and (b) the directional angle ?.
(a) R = km
(b) ? = degrees

Answers

Answer:

a) [tex]R=126Km[/tex]

b) [tex]\theta=74.6\textdegree[/tex]

Explanation:

From the question we are told that:

1st segment

243km at Angle=30

2nd segment

178km West

Resolving to the X axis

[tex]F_x=243cos30+178[/tex]

[tex]F_x=33.44Km[/tex]

Resolving to the Y axis

[tex]F_y=243sin30+178sin0[/tex]

[tex]R=\sqrt{F_y^2+F_x^2}[/tex]

[tex]F_y=121.5Km[/tex]

Therefore

Generally the equation for Directional Angle is mathematically given by

[tex]\theta=tan^{-1}\frac{F_y}{F_x}[/tex]

[tex]\theta=tan^{-1}\frac{121.5}{33.44}[/tex]

[tex]\theta=74.6\textdegree[/tex]

Generally the equation for Magnitude is mathematically given by

[tex]R=\sqrt{F_y^2+F_x^2}[/tex]

[tex]R=\sqrt{33.44^2+121.5^2}[/tex]

[tex]R=126Km[/tex]

g As they reach higher temperatures, most semiconductors... Selected Answer: have an increased resistance. Answers: have a constant resistance. have an increased resistance. have a decreased resistance.

Answers

Answer:

have an increased resistance

Turning a corner at a typical large intersection in a city means driving your car through a circular arc with a radius of about 25 m. if the maximum advisable acceleration of your vehicle through a turn on wet pavement is 0.40 times the free-fall acceleration, what is the maximum speed at which you should drive through this turn?

Answers

Answer:

9.89 m/s.

Explanation:

Given that,

The radius of the circular arc, r = 25 m

The acceleration of the vehicle is 0.40 times the free-fall acceleration i.e.,a = 0.4(9.8) = 3.92 m/s²

Let v is the maximum speed at which you should drive through this turn. It can be solved as follows :

[tex]a=\dfrac{v^2}{r}\\\\v=\sqrt{ar} \\\\v=\sqrt{3.92\times 25} \\\\=9.89 m/s[/tex]

So, the maximum speed of the car should be 9.89 m/s.

When you stand on tiptoes on a bathroom scale, there is an increase in

A) weight reading.
B) pressure on the scale, not registered as weight.
C) both weight and pressure on the scale.
D) none of the above

Answers

Answer:

B) Pressure on the scale, not registered as weight.

Explanation:

This is because energy (derived from weight) becomes compiled on the tips of your toes, and therefore does not increase your weight, but simply the pressure at a smaller point

Monique walks 360 meters to get to lanier on days when she is early and doesn't get caught by traffic it takes her 60 seconds to get to school how fast was she running

Answers

Answer:

6m/s

Explanation:

We are to calculate the speed of Monique

Speed = Distance/Time

Given

Distance = 360m

Time = 60secs

Substitute

Speed = 360m/60s

Soeed = 6m/s

Hence she was running at 6m/s

A water-balloon launcher with mass 2 kg fires a 0.75 kg balloon with a
velocity of 14 m/s to the west. What is the recoil velocity of the launcher?
What is the answer

Answers

Answer:

5.25 m/s to the east

Explanation:

Applying,

MV = mv.............. Equation 1

Where M = mass of the launcher, V = recoil velocity of the launcher, m = mass of the balloon, v = velocity of the balloon

make V the subject of the equation

V = mv/M............ Equation 2

From the question,

M = 2 kg, m = 0.75 kg, v = 14 m/s

Substitute these values into equation 2

V = (0.75×14)/2

V = 5.25 m/s to the east

A single-turn square loop of wire, 2.00 cm on each edge, carries a clockwise current of 0.240 A. The loop is inside a solenoid, with the plane of the loop perpendicular to the magnetic field of the solenoid. The solenoid has 30.0 turns/cm and carries a clockwise current of 15.0 A. Find:

a. the force on each side of the loop
b. the torque acting on the loop.

Answers

Answer:

Explanation:

a )

Magnetic field inside solenoid B = μ₀ NI ,

μ₀ = 4π x 10⁻⁷ ; N is no of turns per meter length in solenoid and I is current B=  4π x 10⁻⁷ x 30 x 10² x 15

= .0565 T .

Force on each side of square loop = B i L

B is external magnetic field , i is current in loop and L is length of side

Force on each side of square loop = .0565 x .24 x 2 x 10⁻²

= 2.7 x 10⁻⁴ N .

b )

Torque on the loop =  F x d

F is force on one side , d is distance between two sides , that is side of the square loop

= 2.7 x 10⁻⁴ x 2 x 10⁻² N.m

= 5.4  x 10⁻⁶ N.m .

When an object is in free fall, ____________________.

Answers

Answer:

Objects that are said to be undergoing free fall, are not encountering a significant force of air resistance; they are falling under the sole influence of gravity.

Explanation:

Under such conditions, all objects will fall with the same rate of acceleration, regardless of their mass.

what does it mean to do science

Answers

Answer:

Doing science could be defined as carrying out scientific processes, like the scientific method, to add to science's body of knowledge.

When an apple falls towards the earth,the earth moves up to meet the apple. Is this true?If yes, why is the earth's motion not noticeable?

Answers

Answer:

Yes, when an apple falls towards the earth, the apple gets accelerated and comes down due to the gravitational force of attraction used by the earth. The apple also exerts an equal and opposite force on the earth but the earth does not move because the mass of the apple is very small, due to which the gravitational force produces a large acceleration in it (a = F/m) but the mass of the earth is very large, the same gravitational force produces very small acceleration in the earth and we don't see the earth rising towards the apple.

3. You have a variable-voltage power supply and a capacitor in the form of two metal disks of radius 0.6 m, held a distance of 1 mm apart. What is the largest voltage you can apply to the capacitor without the air becoming highly conductive

Answers

Answer:

The breakdown of air occurs at a maximum voltage of 3kV/mm.

Explanation:

The breakdown of air occurs at a maximum voltage of 3kV/mm.

At this level of voltage the air between the plates become highly ionised and breakdown occurs. Since, the distance held between the plates is 1mm , it can withstand a maximum voltage of 3 kV.

After this voltage the air will become conductive in nature and will form ions in the air between the plates and ultimately breakdown will take place with a flash.

Convierta 8.5mW a cal/h (1 cal=4.186 j)

Answers

Answer:

[tex] = { \bf{2.03 \times {10}^{ - 6} }}[/tex]

convert 2.4 milimetres into metre​

Answers

0.0024

Milimetres are before centimetres and centimetres are before metres

Answer: 2.4 millimeters = 0.0024 meters

Explanation: A millimeter is 1/1000 of a meter. By diving 2.4 by 1000, you get 0.0024.

The velocity-time graph of a body is given. What quantities are represented by (a) slope of the graph and (b) area under the graph?​

Answers

Answer:

a) acceleration

b) displacement

Explanation:

The velocity-time graph is a graph of velocity versus time. The velocity (m/s) would be on the Y-axis while time (s) would be on the X-axis.

a) The slope of a graph is given by: change in Y-axis/change in X-axis = ΔY/ΔX

In a velocity-time graph, ΔY = change in velocity and ΔX = change in time.

Hence, the slope of a velocity-time graph becomes: change in velocity/change in time.

Also, acceleration = change in velocity/change in time.

Hence, the slope of a velocity-time graph = acceleration.

b) Assuming that the area under a velocity-time graph is a rectangle, the area is given as:

Area of a rectangle = length x breadth

                                  = velocity x time (m/s x s)

Also, displacement = velocity x time (m)

Hence, the area under a velocity-time graph of a body would give the displacement of the body.

An electron has an initial speed of 8.06 x10^6 m/s in a uniform 5.60 x 10^5 N/C strength electic field.The field accelerates the electron in the direction opposite to its initial velocity.
(a) What is the direction of the electric field?
i. opposite
ii. direction to the electron's initial velocity
iii. same direction as the electron's initial velocity
iv. not enough information to decide
(b) How far does the electron travel before coming to rest? m
(c) How long does it take the electron to come to rest? s
(d) What is the electron's speed when it returns to its starting point?

Answers

Answer:

Explanation:

a)

The force on electron acts opposite to the velocity , and direction of force on electron is always opposite to direction of electric field .

Hence direction of electric field must be in the same  in which electrons travels.

Hence option iii is correct.

b )

deceleration a = force / mass

= qE / m

= 1.6 x 10⁻¹⁶ x 5.6 x 10⁵ / 9.1 x 10⁻³¹

= .98 x 10²⁰ m /s²

v² = u² - 2 a s

0 = (8.06 x 10⁶ )² - 2 x .98 x 10²⁰ s

s = 64.96 x 10¹² / 1.96 x 10²⁰

= 33.14 x 10⁻⁸ m

c ) time required

= 8.06 x 10⁶ / .98 x 10²⁰

= 8.22 x 10⁻¹² s .

d ) Its speed will be same as that in the beginning ie 8.06 x 10⁶ m/s .

Answer:

(a) Option (i)

(b) 6.6 x 10^-4 m  

(c) 8.2 x 10^-11 s

Explanation:

initial velocity, u = 8 .06 x 10^6 m/s

Electric field, E = 5.6 x 10^5 N/C

(a) The direction of field is opposite.

Option (i).

(b) Let the distance is s.  

Use third equation of motion

[tex]v^2 = u^2 + 2 a s \\\\0 = u^2 - 2 \times \frac{qE}{m}\times s\\\\8.06\times 10^6\times 8.06\times 10^6 = \frac {1.6\times 10^{-19}\times 5.6\times 10^5}{9.1\times 10^{-31}} s\\\\s = 6.6\times 10^{-4} m[/tex]

(c) Let the time is t.

Use first equation of motion.

[tex]v = u + a t \\\\0 = u - \times \frac{qE}{m}\times t\\\\8.06\times 10^6 = \frac {1.6\times 10^{-19}\times 5.6\times 10^5}{9.1\times 10^{-31}} t\\\\t = 8.2\times 10^{-11} s[/tex]

Which of the following represents the velocity time relationship for a falling apple?

Answers

Answer "a" would be correct.

Answer:

d

Explanation:

There's an acceleration from gravity, thus the velocity is becoming faster and faster as it reaches the ground. Thus its D

Brainliest please~

A cat's displacement is 15 meters to the right in 7.0 seconds. If, at the start of the 7.0 seconds, the cat was moving at a velocity of 2.0 m/s left what was its final velocity?

Answers

Answer:

6.3 m/s

Explanation:

From the given information:

The displacement (x) = 15 m

time (t) = 7.0 s

initial velocity = -2.0 m/s (since it is moving in the opposite direction)

We need to determine the acceleration then find the final velocity.

By applying the kinematics equation:

[tex]x = ut + \dfrac{1}{2}at^2[/tex]

[tex]15 = (-2.0)(7.0) + \dfrac{1}{2}a(7.0)^2\\ \\ 15 = -14.0 + \dfrac{49}{2}a \\ \\ 29= 24.5a \\ \\ a= \dfrac{29}{24.5} \\ \\ a = 1.184 \ m/s^2[/tex]

Now, to determine the final velocity by using the equation:

v = u + at

v = -2 + 1.184(7.0)

v = 6.288 m/s

v ≅ 6.3 m/s

Find the refractive index of a medium
having a velocity of 1.5 x 10^8*

Answers

Explanation:

refractive index ,is the ratio of velocity of light in vacuum to the velocity of light a medium

A body of mass 2kg is released from from a point 100m above the ground level. calculate kinetic energy 80m from the point of released.​

Answers

Answer:

1568J

Explanation:

Since the problem states 80 m from the point of drop, the height relative to the ground will be 100-80=20m.

Use conservation of Energy

ΔUg+ΔKE=0

ΔUg= mgΔh=2*9.8*(20-100)=-1568J

ΔKE-1568J=0

ΔKE=1568J

since KEi= 0 since the object is at rest 100m up, the kinetic energy 20meters above the ground is 1568J

Differentiate between Scalar quantity and Vector quantity and give two examples each​

Answers

Answer:

A scalar quantity is a physical quantity which only has magnitude. Scalars can be added algebraically.A vector quantity is a physical quantity which has both magnitude and direction. Vectors should be added vectorially.

Find the magnitude and direction of a force between a 25.0 coulomb charge and a 40.0coulomb charge when they are separated by a distance of 30.0cm

Answers

Answer:

95.0 colomb

Explanation:

Make sure to understand the concept

David is driving a steady 30 m/s when he passes Tina, who is sitting in her car at rest. Tina begins to accelerate at a steady 2.0 m/s2 at the instant when David passes. How far does Tina drive before passing David?

Answers

a. 441 m B: 46.0 m/s

At which point is the kinetic energy of the pendulum the greatest?

C

A

D

B

Answers

Answer:

Point C

Explanation:

Greatest Kinetic Energy means lowest potential energy since energy is conserved. Lowest potential energy means lowest height which is at Point C.

0. The temperature of source is 500K with source energy 2003, what is the temperature of sink with sink energy 100 J? a. 500 K b. 300 K c. 250 K d. 125 K​

Answers

Answer:

c. 250k

Explanation:

The temperature of the sink is approximately 250 K.

To find the temperature of the sink, we can use the formula for the efficiency of a heat engine:

Efficiency = 1 - (Temperature of Sink / Temperature of Source)

Given that the temperature of the source (T_source) is 500 K and the source energy (Q_source) is 2003 J, and the sink energy (Q_sink) is 100 J, we can rearrange the formula to solve for the temperature of the sink (T_sink):

Efficiency = (Q_source - Q_sink) / Q_source

Efficiency = (2003 J - 100 J) / 2003 J

Efficiency = 1903 J / 2003 J

Efficiency = 0.9497

Now, plug the efficiency back into the first equation to solve for T_sink:

0.9497 = 1 - (T_sink / 500 K)

T_sink / 500 K = 1 - 0.9497

T_sink / 500 K = 0.0503

Now, isolate T_sink:

T_sink = 0.0503 * 500 K

T_sink = 25.15 K

Since the temperature should be in Kelvin, we round down to the nearest whole number, which is 25 K. Thus, the temperature of the sink is approximately 250 K.

To learn more about sink energy, here

https://brainly.com/question/10483137

#SPJ2

The pressure exerted at the bottom of a column of liquid is 30 kPa. The height of the
column is 3,875 m. What type of liquid is used?

Answers

Answer:

For example, the pressure acting on a dam at the bottom of a reservoir is ... pressure = height of column × density of the liquid × gravitational field ... The density of water is 1,000 kg/m 3.

Other Questions
Write the dimension of a / b in the x = at + bt2. Where x is the distance and t is the time? HELLLPPP 31 kilograms is the same as how many pounds? Hint: 1 kg = 2.2 lb Round your answer to the nearest tenth. how does modern erra differ from middle ages A polynomial function has real coefficients, a leading coefficient of 1, and the zeros -6, 1, and 1. Write a polynomial function of least degree in standard form. make a conversation between two people about the situation of odering a product on phone the perimeter The area of squre Plat is 100 m Find at the plot o a Draus Products Company uses activity-based costing to compute product costs for external reports. The company has three activity cost pools and applies overhead using predetermined overhead rates for each activity cost pool. Estimated costs and activities for the current year are presented below for the three activity cost pools.Estimated Overhead Cost Expected ActivityActivity #1 $60,048 4,800Activity #2 $58,656 2,400Activity #3 $130,324 4,400Actual costs and activities for the current year were as follows. Actual Overhead Cost Actual ActivityActivity #1 $59,798 4,830Activity #2 $58,476 2,370Activity #3 $130,234 4,450The total amount of the debits to the manufacturing overhead during the year was closest to:__________. a. $248,508. b. $248,988. c. $250,334.d. $251,110. What improvements were made in measuring system with the introduction of standard units? why do we feel cold when we go to the high altitude ? Don't copy paste A postal worker can sort a day's worth of mail in 8 hours. With hersupervisor helping, it takes 3 hours. How long would it take thesupervisor working alone? please, help! i really need it !! like rnnn! akram is 20 year old and his sister shazia is 15 1-what was the ratio of their ages before 4 years2-what was the ratio of their ages after 5 years3-what do the above two points explain about ratios Find the length of side x in simplest radical form with a rational denominator.4.60930xCAnswer: How do you say "teddy bear" in Spanish? What was the Final Solution, and how was it developed? Answer asap and I will give a like, brainlist ,and 50 points Find the product of 2x cubed and x squared minus 5x minus 4. Problem number 23 please help me !! :) word meaning ofglade Rotate the vector 3,-2 90 degrees clockwise about the origin.