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
Which of the following is not a vector quantity?
Speed
Velocity
Torque
Displacement
The vectors and are such that | + | = | - | then angle between the two vectors will be
45°
60°
75°
90°
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 magnitudes of vectors are 3,4 and 5 units respectively. If , the angle between is
cos-1 (0.6)
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
The angle between the two vectors will be
0°
180°
When milk is churned, cream gets separated due to
centripetal force
centrifugal force
frictional force
gravitational force
The resultant of × 0 will be equal to
zero
A
zero vector
unit vector