1800-150-456-789
FlagBACK
Flag General Physics> A particle moving with uniform accelerati...
question mark

A particle moving with uniform acceleration along a straight line passes through successive points P, Q, R where PQ:QR = 3:5 and time taken from P to Q is 40 seconds. If the velocity of the particle at P and R are 10m/s and 30m/s. Find:
  1. The velocity of the particle at Q
  2. The acceleration of the particle.
  3. Time taken to cover Q to R.
  4. Total time from P to R.

Arshad Ali , 8 Years ago
Grade 11
anser 2 Answers
Naveen Kumar

Last Activity: 8 Years ago

______________________________
P.                 Q.                             R
←.  3.    →.    ←.       5.           →
 
From P to R
u = 10m/s.    v = 30 m/s.     S =8 m ( let 3 + 5 )
v2 = u2 + 2as
900 = 100 + 16a  ( after putting values)
=> 16a = 800
=> a = 800/16
=> a = 50 m/s2. .            ACCELERATION
 
Therefore velocity v2 at Q is
u = 10m/s.   a = 50m/s2.      S = 3
 
v2 = u2 + 2as
v2 = 100 + 2*50*3
v = 20m/s.                      VELOCITY
 
Time from Q to R
u = 20m/s.           v= 30m/s.      a = 50m/s2
v = u + at
t = v-u/a
t = ( 30 - 20)/50
t= 0.2 seconds.                          TIME
 
Vikas TU

Last Activity: 8 Years ago

Dear Student,
U might like this one better:

Let the velocity at point Q is x.
PQ:QR = 3:5
let it be 3y and 5y

v2-u2=2as
=>900-x2=2xax5y
=>10ay=900-x2 ------1

velocity of the particle at P and R are 10m/s and 30m/s
solving this by putting v2-u2=2as
gives
900-100=2xax8y
=>ay=50

substituting ay in 1
=>10x50=900-x2
=>x=20m/s
 
Cheers!!
Regards,
Vikas (B. Tech. 4th year
Thapar University)
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Other Related Questions on general physics

question mark
moment of inertia of a equilateral triangle about an axis passing through centre and perppendicular to the plane
general physics
1 Answer Available

Last Activity: 2 Years ago

question mark
. Because of the rotation of the earth, a plumb bob may not hang exactly along the direction of
the earth’s gravitational pull (its weight) but deviates slightly from this direction. Calculate the
deviation (a) at 40 latitude, (b) at the poles, and (c) at the equator
general physics
1 Answer Available

Last Activity: 2 Years ago

question mark
The length of a massless rod is measured using vernier callipers having 10 vernier scale divisions and least count of 0.1 mm. Two masses 1.00 ± 0.01 kg and 4.00 ± 0.02 kg are attached to its ends. If reading of vernier scale is 5 divisions coinciding with 1.3 cm, what is the % error in locating centre of mass from lighter mass
general physics
2 Answers Available

Last Activity: 2 Years ago

question mark
A block is kept on x-y plane at a point (2m,3m). It is pushed with a force of magnitude 10 Ntowards point (5m,7m). The force can be represented as?
general physics
1 Answer Available

Last Activity: 2 Years ago

question mark
The phase of particle at t is 70°and another particle is at t is 790° what is wavelength if the distance between two particles is1 m
general physics
1 Answer Available

Last Activity: 3 Years ago