Physics-
General
Easy
Question
The driver of a car moving with a speed of 
sees a red light ahead, applies breaks and stops after covering 10m distance. If the same car were moving with a speed of 
, the same driver would have stopped the car after covering 30 m distance. Within what distance the car can be stopped if travelling with a velocity of 15
Assume the same reaction time and the same deceleration in each case.
- 18.75 m
- 20.75 m
- 22.75 m
- 25 m
The correct answer is: 18.75 m
If 
is the reaction time, then the distance covered during decelerated motion is 
.
Now, in the first case,
(i)
Similarly, in the second case,
(ii)
Again, in the third case,
.(iii)
Dividing Eq.(ii) by Eq. (i),
or 
or 
or 
Dividing Eq. (iii) by Eq. (i), we get
or 
or 
or 
m
Related Questions to study
Physics-
In a race for 100m dash, the first and the second runners have a gap of one metre at the mid way stage. Assuming the first runner goes steady, by what percentage should the second runner increases his speed just to win the race.
In a race for 100m dash, the first and the second runners have a gap of one metre at the mid way stage. Assuming the first runner goes steady, by what percentage should the second runner increases his speed just to win the race.
Physics-General
Physics-
A balloon starts rising from the ground with an acceleration of 
after 8s, a stone is released from the balloon. The stone will 
A balloon starts rising from the ground with an acceleration of after 8s, a stone is released from the balloon. The stone will
Physics-General
Physics-
The given graph shows the variation of velocity with displacement. Which one of the graph given below correctly represents the variation of acceleration with displacement?
The given graph shows the variation of velocity with displacement. Which one of the graph given below correctly represents the variation of acceleration with displacement?Physics-General
Physics-General
Physics-
The displacement-time graphs of two moving particles make angles of 
with the 
axis. The ratio of their velocities is
The displacement-time graphs of two moving particles make angles of with the axis. The ratio of their velocities isPhysics-General
Physics-General
Physics-
If the velocity of particle is given by 
, then its acceleration will be
If the velocity of particle is given by , then its acceleration will be
Physics-General
Physics-
A man drops a ball downside from the roof of a tower of height 
. At the same time another ball is thrown upside with a velocity 
. From the surface of the tower, then they will meet at which height from the surface of the tower
A man drops a ball downside from the roof of a tower of height . At the same time another ball is thrown upside with a velocity . From the surface of the tower, then they will meet at which height from the surface of the tower
Physics-General
Physics-
Two balls 
and 
of same masses are thrown from the top of the building. , thrown upward with velocity 
and , thrown downward with velocity , then
Two balls and of same masses are thrown from the top of the building. , thrown upward with velocity and , thrown downward with velocity , then
Physics-General
Physics-
The distance travelled by a particle is proportional to the square of time, then the particle travels with
The distance travelled by a particle is proportional to the square of time, then the particle travels with
Physics-General
Physics-
The graph between the displacement 
and 
for a particle moving in a straight line is shown in figure. During the interval 
and 
the acceleration of the particle is
, 
The graph between the displacement and for a particle moving in a straight line is shown in figure. During the interval and the acceleration of the particle is
,
Physics-General
Physics-
The acceleration of a particle increases linearly with time as 6. If the initial velocity of the particle is zero and the particle starts from the origin, then the distance travelled by the particle in time will be
The acceleration of a particle increases linearly with time as 6. If the initial velocity of the particle is zero and the particle starts from the origin, then the distance travelled by the particle in time will be
Physics-General
Physics-
A stone dropped from a balloon which is at a height 
reaches the ground after second. From the same balloon, if two stones are thrown, one upwards and the other downwards, with the same velocity 
and they reach the ground after 
second respectively, then
A stone dropped from a balloon which is at a height reaches the ground after second. From the same balloon, if two stones are thrown, one upwards and the other downwards, with the same velocity and they reach the ground after second respectively, then
Physics-General
Physics-
A particle moves along a straight line 
. At a time (in seconds) the distance (in metres) of the particle from 
is given by 
How long would the particle travel before coming to rest
A particle moves along a straight line . At a time (in seconds) the distance (in metres) of the particle from is given by
How long would the particle travel before coming to rest
Physics-General
Physics-
The position 
of a particle varies with time 
as 
The acceleration of the particle will be zero at time equal to
The position of a particle varies with time as The acceleration of the particle will be zero at time equal to
Physics-General
Physics-
A car moving with speed of 
can be stopped by applying brakes after atleast 
. If the same car is moving with a speed of 
, what is the minimum stopping distance
A car moving with speed of can be stopped by applying brakes after atleast . If the same car is moving with a speed of , what is the minimum stopping distance
Physics-General
Physics-
An object start sliding on a frictionless inclined plane and from same height another object start falling freely
An object start sliding on a frictionless inclined plane and from same height another object start falling freely
Physics-General
