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
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
When milk is churned, cream gets separated due to
centripetal force
centrifugal force
frictional force
gravitational force
A boat is sent across a river with a velocity of 8 km h-1. If the resultant velocity of boat is 10 km h-1 , then velocity of river is
12.8 km h-1
6 km h-1
8 km h-1
10 km h-1
A body is whirled in a horizontal circle of radius 20 cm. It has an angular velocity of 10 rad/s. What is its linear velocity at any point on circular path?
√2 m/s
2 m/s
10 m/s
20 m/s
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
zero
50 km/h along west
70.7 km/h along north-west direction
The maximum range of a gun of horizontal terrain is 16 km. If g = 10 ms-2 , then muzzle velocity of a shell must be
160 ms-1
200√2 ms-1
400 ms-1
800 ms-1
The angle between and is θ. The value of the triple product .( × ) is
A2B
A2B sin θ
A2B cos θ
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
A bullet is fired from a gun with a speed of 100 m/s in order to hit a target 100m away. At what height above the target should the gun be aimed? (The resistance of air is negligible and g = 10 m/s2)
5 cm
10 cm
15 cm
20 cm