The resultant of × 0 will be equal to
zero
A
zero vector
unit vector
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
When a body moves with a constant speed along a circle
its velocity remains constant
no force acts on it
no work is done on it
no acceleration is produced it
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
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
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 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 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 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 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
