Ask a Doubt
Request a call back

Join NOW to get access to exclusive study material for best results

JEE Class main Answered

A car loaded with sand is moving with spped v .a hole is present at bottom of car through sand is falling continuously.then after time t velocity of car is increase or decrease
Asked by ashutosharnold1998 | 31 Aug, 2019, 00:34: AM
answered-by-expert Expert Answer
Let us assume car is moving with constant speed V and there is no external force.
 
(Let us assume the force generated by engine just balances the frictional force between car tyres and ground.
Hence net force acting on moving car is zero)
 
Let M be the mass of car and m be the mass of sand falling from car in every second.
 
At the time of falling , sand particles get a horizontal velocity V .
 
Hence if we apply momentum conservation for time instants of before sand falling and after time falling we get,
 
M×V =  m×V + (M-m)×V1 .....................(1)
 
eqn.(1) is rewritten as,   M×V = m×(V - V1) + M×V1 ..................(2)
 
Though (V - V1) is negligible,  m×(V-V1) is +ve .  Hence from eqn.(2), we get  V1 < V
 
Hence the speed of car decreases
 
Answered by Thiyagarajan K | 31 Aug, 2019, 08:57: AM

Application Videos

Concept Videos

Multiple Choice Questions Practice Test
Answered Unanswered My Questions My Answers
JEE main - Physics
a marble block of mass 2 kg lying on ice when a given velocity of 6 ms–1 is stopped by friction in 10 seconds then co efficient of friction is
Asked by sumalathamadarapu9 | 23 Oct, 2024, 22:06: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
show that the frequency of oscillations remain unchanged whether a mass attached to a spring is made to oscillate in the vertical or in the horizontal direction
Asked by py309649 | 13 Oct, 2024, 13:39: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
Square of the time period of revolution of a planet is proportional to the cube of the mean distance between sun and planet. If mean distance is increased by 2% then percentage change in its time period is
Asked by coolskrish | 13 Oct, 2024, 12:50: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
two particles of mass m and 4m are initially actress the sad moving towards each other due to mutual gravitational force at an instantly of m is vî then at this instant the velocity of mass 4m is
Asked by midnightmoon3355 | 09 Oct, 2024, 09:09: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
what is the second law of thermodynamics
Asked by rambabunaidu4455 | 03 Oct, 2024, 16:03: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
what is the relation between drift velocity and mobility
Asked by ratchanavalli07 | 17 Sep, 2024, 07:46: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
A ball of mass m approaches a moving wall of infinite mass with speed v along the normal to the wall. The speed of the ball is u towards the ball. The speed of the ball after elastic collision with the wall is
Asked by yayashvadutta45 | 15 Sep, 2024, 19:47: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
a current of 2a is flowing through a conductor of length 22m bent in arc radius 5cm
Asked by adithireddy999 | 03 Sep, 2024, 09:35: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
two vectors vector a and vector B lie in one plane vector c lie in the different plane then vector a + vector b + vector c is
Asked by vaishalinirmal739 | 29 Aug, 2024, 18:07: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
JEE main - Physics
What is impulse?
Asked by vradhysyam | 26 Aug, 2024, 17:17: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
My Class Videos Tests ₹ Plans Ask a Doubt