Banner 0
Banner 1
Banner 2
Banner 3
Banner 4
Banner 5
Banner 6
Banner 7
Banner 8
Banner 9

Q.

The speed of a train increases at a constant rate α from zero to v and then remains constant for an interval and finally decreases to zero at a constant rate β. The total distance travelled by the train is l. The time taken to complete the journey is t. Then,

see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya

a

t=l(α+β)αβ

b

t=lv+v21α+1β

c

t is minimum when v=2lαβ(α-β)

d

t is minimum when v=2lαβ(α+β)

answer is B.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

JEE

NEET

NEET

Foundation JEE

Foundation JEE

Foundation NEET

Foundation NEET

CBSE

CBSE

Detailed Solution

ν=αt1⇒t1=ναv=βt2⇒t2=vβ∴ t0=t-t1-t2=t-vα-vβNow, l=12αt12+vt0+12βt22=12(α)vα2+vt-vα-vβ+12(β)vβ2=vt-v22α-v22β∴ t=lv+v21α+1βFor t to be minimum its first derivation with respect to velocity be zero, i.e.0=-1v2+α+β2αβ∴v=2lαα+β
Watch 3-min video & get full concept clarity
score_test_img

courses

No courses found

Get Expert Academic Guidance – Connect with a Counselor Today!

best study material, now at your finger tips!

  • promsvg

    live classes

  • promsvg

    progress tracking

  • promsvg

    24x7 mentored guidance

  • promsvg

    study plan analysis

download the app

gplay
mentor

Download the App

gplay
whats app icon
personalised 1:1 online tutoring