1Some1 try these out, yaar, pleaaaase.
1.. 2 boats A and B move away from buoy anchored @ the middle of the river along mutually
perpendicular straight lines,the boat A along the river and the boat B across the river. Having
moved off an equal distance from the buoy the boat returned. Find the times of motion of the
boats tA/tB if the velocity of each boat with respect to water is n times greater than the stream velocity.
[ans= (n/√n2-1) ]
2.. Two particles move in a uniform gravitational field with an acceleration g. At the initial moment,the particles were located @ 1 point in space and moved with velocities v1=3 m/s and v2=4m/s horizontally in opposite directions. Find the distance between the particles @ the moment when their velocity vectors become mutually perpendicular.
[ans=2.42 m]
3. A motorboat is to reach @ a point 30° upstream on the other side of a river flowing with velocity 5m/s. velocity of motorboat wrt water is 5√3 m/s. The driver should steer the boat at an angle of _________.
[ans=60° wrt normal to the bank]
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8 Answers
11ST and 2ND one going over my head. so, i need someone to solve it for me
3RD ONE:: I CANT COMPREHEND IT FULLY
11) FOr boat A, t1 = xv(n+1)
t2 = xv(n-1)
so tA = t1 + t2 = 2xnv(n2 - 1)
For boat B, tB = 2xv√(n2 - 1)
hence tAtB = n√(n2 - 1)
12) v1 = -3i - gtj
v2 = 4i - gtj
v1.v2 = 0 => t = √35s
now find out distance moved by the two and hence the distance...
1For 3rd thats 30° upstream measured from the normal or with the flow of river????
1i think i've 2 work backwards, starting from the answer to get this 1.