JEE Class main Answered
A bullet looses ^{th})
of its velocity passing through one plank. The number of such planks that are required to stop the bullet can be :
a)
b)
c)
Infinite
d)
Hide
Asked by Ranjeetgupta26068 | 17 May, 2019, 03:29: PM
Expert Answer
Formula to be used : v2 = u2 - 2aS ; where v is final speed , u is initial speed, a is retardation and S is the distance travelled.
Let u be initial speed and u[ 1 - (1/n)] be the final speed after going through one plank.
then we have, u2[ 1 - (1/n) ]2 = u2 - 2 a S ................(1)
where a is retardation and S is plank thickness.
from (1) we get, retardation a = u2 [ 1 - { 1 - (1/n) }2 ] / (2S) = u2 [ (2/n) - (1/n)2 ] / (2S) = u2 (2n-1)/( 2S n2 )..............(2)
if m planks are required to stop the bullet, then we have u2 - 2[ ( u2 (2n-1) /(2S n2 )] m S ) = 0 .................(3)
Hence from eqn.(3), we get m = n2 / ( 2n - 1 )
Answered by Thiyagarajan K | 17 May, 2019, 10:44: PM
Application Videos
-
Elastic potential energy_Restoring force and spring con ...
In this video, the restoring force and spring constant is explained. The vi... -
Expression of Elastic potential energy_2
This video describes the potential energy of spring when it is compressed o... -
Potential Energy Curve
This video describes the potential energy curve and ature of forces based o... -
Work done by static friction
This video describes effect of static friction on the work done by the obje... -
Work done in conservative field - 1
The concept of conservative field, types of conservative forces and example...
JEE main - Physics
Asked by mohammedimroz | 13 Apr, 2024, 09:48: PM
ANSWERED BY EXPERTJEE main - Physics
Asked by medhamahesh007 | 02 Apr, 2024, 11:11: AM
ANSWERED BY EXPERTJEE main - Physics
Asked by gundlasumathi93 | 31 Mar, 2024, 02:13: PM
ANSWERED BY EXPERTJEE main - Physics
Asked by chhayasharma9494 | 31 Mar, 2024, 12:47: PM
ANSWERED BY EXPERTJEE main - Physics
Asked by archithateja3 | 30 Mar, 2024, 10:23: PM
ANSWERED BY EXPERTJEE main - Physics
Asked by Machinenineha | 27 Mar, 2024, 05:28: PM
ANSWERED BY EXPERT
JEE main - Physics
Asked by mfkatagi099 | 20 Mar, 2024, 09:35: PM
ANSWERED BY EXPERTJEE main - Physics
Asked by sreelekhachakali2006 | 15 Mar, 2024, 10:35: AM
ANSWERED BY EXPERT
