1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
denis-greek [22]
3 years ago
12

On a journey of 600 km, a train was delayed 1 hour and 30 min after having covered 1 4 of the way. To arrive on time at the dest

ination, the engine driver had to increase the speed by 15 km/hour. How long did the train travel for
Physics
1 answer:
mars1129 [50]3 years ago
5 0

Answer:

The train travelled 10hours.

Explanation:

Using speed= distance/time ...eq1

Let the time taken by train to cover the journey be t.

Let the speed of train be s

Time= distance/speed ...eq2

Time t =600/s ...eq3

The train is delayed for 1 1/2 hours=3/2 hours

Train increased by 15km/hr.

Train travelled 1/4 of 600k.= 150km.

Speed increased by s + 15 to cover the remaining 450km

t = 150/s + 400/(s + 15) + 3/2 ..eq4

Equating eq3 and 4

600/s= 150/s + 460/(s + 15) + 3/2

450/s = 3/2 + 450/(s + 15)

3s^2 + 45s -13500=0

Solving the quadratic equation

S= -45 +-sqrt(45^2-4(3×13500)/2×3

S= 60 , -75

Hence speed of train is 60km/hr

Using eq 2 distance/speed=time

600/60=10

t= 10hours

You might be interested in
A disk with a radius of R is oriented with its normal unit vector at an angle Θ with respect to a uniform electric field. Which
marissa [1.9K]

Answer:

The expresion for the flux through the disk is:

Ф = E·πR^2·cos(Θ).

Explanation:

Let's sat the electric field has direction e and the normal to the disk has direction n (bold means vector quantities). So we have:

E=E·e (where E is the magnitud of the electric flied)

A=A·n

The flux for an uniform electric field and a flat surface is:

Ф=E×A

⇒ Ф = E·A·e×n = E·A·cos(angle(e,n)) = E·A·cos(Θ)

Since in this case the area is for a disk of radius R, A=\pi R^{2}

So, Ф = E·πR^2·cos(Θ)

8 0
3 years ago
Read 2 more answers
A ball whose mass is 0.3 kg hits the floor with a speed of 5 m/s and rebounds upward with a speed of 2 m/s. If the ball was in c
Sonbull [250]

Answer:

1400 N

Explanation:

Change in momentum equals impulse which is a product of force and time

Change in momentum is given by m(v-u)

Equating this to impulse formula then

m(v-u)=Ft

Making F the subject of the formula then

F=\frac {m(v-u)}{t}

Take upward direction as positive then downwards is negative

Substituting m with 0.3 kg, v with 2 m/s, and u with -5 m/s and t with 0.0015 s then

F=\frac {0.3(2--5)}{0.0015}=1400N

4 0
3 years ago
This is the smallest unit of matter that cannot be physiologically broken down.
yuradex [85]
An atom is the smallest unit of matter. It can't be broken. It consist of dense nuleus surrounded by negatively charged electrons.
4 0
3 years ago
Define fractional distillation
Serga [27]

Answer:

separation of a liquid mixture into fractions differing in boiling point (and hence chemical composition) by means of distillation, typically using a fractionating column.

7 0
2 years ago
Read 2 more answers
In a elastic lab what did you change and why?
Vilka [71]

I changed my undershorts.  The elastic on the old ones I put on that day was deteriorated, and it completely failed when I dripped lab coffee on it, causing falldown.

7 0
3 years ago
Read 2 more answers
Other questions:
  • Jessica and Martin start riding their bicycles towards each other at 2 pm. At 2 pm, they are 25 miles apart. Jessica rides her b
    12·1 answer
  • The Hubble constant, $H_{0}$, is the ratio of the recessional velocity of a galaxy to its distance. The Hubble constant is estim
    10·1 answer
  • If the amount of gas in a sealed container increases, what happens to the pressure in the container
    10·2 answers
  • The drawing shows three particles far away from any other objects and located on a straight line. The masses of these particles
    10·1 answer
  • An electron experiences a force of magnitude F when it is 5 cm from a very long, charged wire with linear charge density, lambda
    14·1 answer
  • According to the kinetic-molecular theory, gases condense into liquids because of
    14·1 answer
  • What is the speed of an arrow that takes 1.25 seconds to hit a target 75<br> meters away?
    12·2 answers
  • A toy rotates at a constant 5rev/min. is its angular acceleration positive, negative, or zero?
    11·1 answer
  • Please what are the laws of Isaac Newton for Motion​
    13·1 answer
  • Which of the following statements is
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!