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
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
A stone tied to the end of a string of 1 m long is whirled in a horizontal circle with a constant speed. If the stone makes 22 revolutions in 44s, what is the magnitude and direction of acceleration of the stone?
and direction along the radius towards the centre
π2 ms-2 and direction along the radius away from centre
π2 ms-2 and direction along the radius towards the centre
π2 ms-2 and direction along the tangent to the circle
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
What is the linear velocity if angular velocity vector and position vector ?
P is the point of contact of a wheel and the ground. The radius of wheel is 1 m. The wheel rolls on the ground without slipping. The displacement of point P when wheel completes half rotation is
2 m
π m
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 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
Find the torque of a force acting at the point .
and are two vectors and θ is the angle between them, if | × | = √3 ( . ) the value of θ is
60°
45°
30°
90°
