Physics-
General
Easy
Question
A boat crosses a river from port
to port
, which are just on the opposite side. The speed of the water is
and that of boat is
relative to still water. Assume
. What is the time taken by the boat, if It has to cross the river directly on the
line
The correct answer is: 

From figure, 

Time taken to cross the river,

Related Questions to study
Physics-
The effective acceleration of a body, when thrown upwards with acceleration
will be:
The effective acceleration of a body, when thrown upwards with acceleration
will be:
Physics-General
Physics-
A body released from a great height falls freely towards the earth. Another body is released from the same height exactly one second later. The separation between the two bodies two second after the release of the second body is
A body released from a great height falls freely towards the earth. Another body is released from the same height exactly one second later. The separation between the two bodies two second after the release of the second body is
Physics-General
Physics-
If a car at rest accelerates uniformly to a speed of 144
in 20
. Then it covers a distance of
If a car at rest accelerates uniformly to a speed of 144
in 20
. Then it covers a distance of
Physics-General
Physics-
A body stars from rest and falls vertically from a height of 19.6m. If
, then the time taken by the body to fall through the last metre of its fall, is
A body stars from rest and falls vertically from a height of 19.6m. If
, then the time taken by the body to fall through the last metre of its fall, is
Physics-General
Physics-
From the top of a tower two stones, whose masses are in the ratio
are thrown one straight up with an initial speed
and the second straight down with the same speed
. Then, neglecting air resistance
From the top of a tower two stones, whose masses are in the ratio
are thrown one straight up with an initial speed
and the second straight down with the same speed
. Then, neglecting air resistance
Physics-General
Physics-
If a body starts from rest and travels
in the 6th second, then what is the acceleration
If a body starts from rest and travels
in the 6th second, then what is the acceleration
Physics-General
Physics-
From the top of a tower of two stones, whose masses are in the ratio 1 : 2 are thrown on straight up with an initial speed
and the second straight down with the same speed
Then neglecting air resistance
From the top of a tower of two stones, whose masses are in the ratio 1 : 2 are thrown on straight up with an initial speed
and the second straight down with the same speed
Then neglecting air resistance
Physics-General
Physics-
An object, moving with a speed of 6.25 m/s, is decelerated at a rate given by
where
is the instantaneous speed. The time taken by the object, to come to rest, would be
An object, moving with a speed of 6.25 m/s, is decelerated at a rate given by
where
is the instantaneous speed. The time taken by the object, to come to rest, would be
Physics-General
Physics-
A boat is sent across a river with a velocity of boat is
. If the resultant velocity of boat is
then velocity of the river is :
A boat is sent across a river with a velocity of boat is
. If the resultant velocity of boat is
then velocity of the river is :
Physics-General
Physics-
A bus start from rest with an acceleration of
. A man who is 48m behind the bus starts with a uniform velocity of
. The minimum time after which the ma will catch the bus
A bus start from rest with an acceleration of
. A man who is 48m behind the bus starts with a uniform velocity of
. The minimum time after which the ma will catch the bus
Physics-General
Physics-
Speed of two identical cars
and
at a specific instant. The ratio of the respective distances in which the two cars are stopped from that instant is
Speed of two identical cars
and
at a specific instant. The ratio of the respective distances in which the two cars are stopped from that instant is
Physics-General
Physics-
A body freely falling from rest has a velocity
after it falls through distance
. The distance it has to fall down further for its velocity to become double is
A body freely falling from rest has a velocity
after it falls through distance
. The distance it has to fall down further for its velocity to become double is
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-
A particle is moving with constant acceleration from
to
in a straight line
. If
and
are the velocities at
and
respectively then its velocity at the midpoint
will be
A particle is moving with constant acceleration from
to
in a straight line
. If
and
are the velocities at
and
respectively then its velocity at the midpoint
will be
Physics-General
Physics-
The variation of velocity of a particle with time moving along a straight line is illustrated in the following figure. The distance travelled by the particle in four seconds is
The variation of velocity of a particle with time moving along a straight line is illustrated in the following figure. The distance travelled by the particle in four seconds is
Physics-General