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 accelaration of a point on the tip of the blade is
1600ms-2
47.4 ms-2
23.7 ms-2
50.55 ms-2
Two particle A and B are connected by a rigid rod AB .The rod slides along perpenticular rails as shown here.The velocity of A to the rigid is 10 m /s .What is the velocity of B when angle a = 600?
9.8 m/s
10 m /s
5.8 m /s
17.3 m /s
190J
160J
150J
20J
zero
A
zero vector
unit vector
45
75
20
10
A bullet is fired a gun with a speed of 1000 m/s in order to hit a target 100 m 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
600
450
300
900
A particle of mass m is projected with velocity v making an angle of 450 with the horizontal.When the particle lands on the level ground the magnitude of the change in its momentum will be
2 mv
mv / √2
mv √2
directed towards the origin
directed away from the origin
parallel to the position vector
perpenticular to the position vector
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 900,the increase in the velocity of bus in the turning process is
70.7 km/h along south - west direction.
50 km/h along west
70.7 km/h along north- west direction
