The speed of a boat is 5 km / h in still water.It crosses a river of width 1.0 km along the shortest possible path in 15 min.The velocity of the river water is in (km / h)
5
1
3
4
When a body moves with a constant speed along a circle
Its velocity remains constant
No force act on it
No work is done on it
No acceleration is produced in it
450
600
750
900
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 are projected with same initial velocities at angle 300 and 600 with the horizontal .Then
their height will be equal
their ranges will be equal
their time of flights will be equal
their ranges will be different
cos-1 (0.6)
When milk is churned ,cream gets separated due to
centripetal force
centrifugal force
frictional force
gravitational force
A car runs at a constant speed on a circular track of radius 100 m, taking 62.8 s for every circular lap. The average velocity and average speed for each circular lap respectively is
0,0
0,10 m/s
10m/s,10m/s
10m/s,0
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
A stone tied to the end of a string of 1m long is whiriled 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?
π2/4 ms-2 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
