v
v ector 127
A man can swim at the rate of 4 km.h-l in still nter. At
What should the man Set himself relative to the current
2 • to the river perpendicular to
[HS(XI)
A river is 150 m Wide and has a current Of m s—l. A
moving directly across the river at a speed of 2 m s-l. How
[9001
what is the
— cm•s-l
e and then
re• Find the
1b cose m I
and finally
m the orig-
10m west'
e Of magni-
itude of the
. 25 dynl
and north-
ie forces by
. the northl
ed to each
men is
oint. mak-
'4.51 dynl
to move
ticany
$8.57 N I
other car
•locity Of
the wet]
appar-
ing hori-
IHS '041
IS.
16.
18.
19.
20.
21.
22.
23.
24.
long will the boat take to cross the river?
175s1
17. A boat is moving at 12 km • h-i trmards north and anoth«
boat is moving at 1244 km towards north-west. Find
the relative Vdocity of the second boat With to the
12 km • Low•ards w•tl
A ship is moving at 40 km •
proceeding south at 30 h -l . Find the relative velocity of
the second with respect to the first.
150 km • h-l . inclined towards east making an angle tan-1
With the southl
From the top Of a tower, two particles are dropped at an inter-
val of 2 s. Find the relative velocity and relative accderation of
the particles during the fall. Acceleration due to gravity
—g cm.s-2.
crn•s-l , 01
In a harbour. Wind is at the speed Of 72 km •
the flag on the mast of a boat anchored in the harbour flutters
along the N-E direction. Ifthe boat starts moving at a sp«f of
51 km • h-L to the north. What Will be the Of
on the mast of the boat?
INCERTI
ieast (approx)l
To a cyclist moving at 5 m • s-l , rain appears to be falling
tically at a veltxity 5 m • . Find the actual magnitl&
direction of the velocity of rain.
m •s-l , 450 the verticall
A river 1 km wide is flowing at 3 km • h-l . A swimmer whog:
velocity in still water is 4 km • h-l can swim only 15 min-
utes. In what direction should he strike-out in order to reach
opposite bank in 15 minutes? What total distance he
(at right angle to the flow of water; I .25 km I
A boat which has a speed of 5 km h-l in still water crosses a
river of width 1 along the shortest possible path in 15
13 km• h-ll
minutes. What is the velocity of river water?
An aeroplane is flying eastward with a speed of km • h-l
Wind in blowing southward with a speed of 100 km • h-l . Cal-
curate the and direcü)n Of the With
1608.28 km• at 9028' south of east)
to the ground.
• Based on Multiplication of Vectors
If and a b • c, What is the angle between
vectors and
and —3i•2j are Find the
the two
