A particle is projected at an angle with horizontal with an initial speed u. When it makes an angle with horizontal, its speed is
1. u cos
2. u cos cos
3.
4.
A ship A is moving westwards with a speed of 10 km h-1 and a ship B, 100 km south of A is moving northwards with a speed of 10 km h-1. The time after which the distance between them becomes the shortest, is:
1. 5 hr
2.
3.
4. 0 hr
Three particles moving with constant velocities respectively as given as figure. After some time all three particles are in the same line, then relation among is:
1.
2.
3.
4.
A river is flowing with a speed of 1 km/hr. A simmer wants to go to point 'C' starting from 'A'. He swims with a speed of 5km/hr, at an angle with respect to the river. If AB=BC=400 m. Then-
1. time taken by the mass is 12 min
2. time taken by the man is 8 min
3. the value of is 45
4. the value of is 53