The position vector of a particle, is . The velocity of the particle is
directed towards the origin
directed away from the origin
parallel to the position vector
perpendicular to the position vector
A person swims in a river aiming to reach exactly opposite point on the bank of a river. His speed of swimming is 0.5 m/s at an angle 120° with the direction of flow of water. The speed of water in stream is
1.0 m/s
0.5 m/s
0.25 m/s
0.43 m/s
A body constrained to move in Y-direction is subjected to a force given by . What is the work done by this force in moving the body through a distance of 10 m along Y-axis?
190 J
160 J
150 J
20 J
The magnitudes of vectors are 3,4 and 5 units respectively. If , the angle between is
cos-1 (0.6)
An electric fan has blades of length 30 cm measured from the axis of rotation. If the fan is rotating at 120 rev/min, the acceleration of a point on the tip of the blade is
1600 ms-2
47.4 ms-2
23.7 ms-2
50.55 ms-2
The angle between and is θ. The value of the triple product .( × ) is
A2B
zero
A2B sin θ
A2B cos θ
A bus is moving on a straight road towards north with a uniform speed of 50 km/h. If the speed remains unchanged after turning through 90°, the increase in the velocity of bus in the turning process is
7.07 km/h along south-west direction
50 km/h along west
70.7 km/h along north-west direction
A particle moves along a circle of radius with constant tangential acceleration. If the velocity of the particle is 80 m/s at the end of the second revolution after motion has begun, the tangential acceleration is
160 π m/s2
40 m/s2
40 π m/s2
640 π m/s2
Two bodies of same mass are projected with the same velocity at an angle 30° and 60° respectively. The ratio of their horizontal ranges will be
1 : 1
1 : 2
1 : 3
1 : √2
When milk is churned, cream gets separated due to
centripetal force
centrifugal force
frictional force
gravitational force
