Question

MULTIPLE OBJECTIVE TYPE 1. Two particles A and B projected along different directions from the same point P on the ground with the same speed of 70 m/s in the same vertical plane. They hit the ground at the same point Q such that PQ = 480 m. Then : (Use g = 9.8 m/s2, sin-1 0.96 = 74º, sin-10.6 = 37°) (a) ratio of their time of flights is 4:5 (b) ratio of their maximum heights is 9:16 (c) ratio of their minimum speeds during flight is 4:3 (d) the bisector of the angle between their directions of projection makes 45° with horizontal

JEE/Engineering Exams

Physics

Solution

218

4.0 (1 ratings)

( 488=70 times 70 times 10 times 20 ) 0.96 ( frac{24}{25} frac{48}{50}=11 ) ( t_{2}=frac{24 frac{1}{9} cos theta}{g} ) ( t_{1}: t_{2}=frac{201 sin 0 . x 85}{8 times 200 cos 0}=frac{sin theta}{cos theta}=mid tan 37 ) ( S_{0}, quad t_{1}: t_{2} Rightarrow quad 3=4 ) ( n,=h_{2} Rightarrow frac{1+^{2} sin ^{2} Q}{2 g^{2} times cos ^{2} cos ^{2} alpha}=left(frac{sin theta}{cos alpha}right)^{2} ) ( =[9: 16) ) So, the painimunm &peed is at homer 50 ( left.frac{V_{min }(1)}{V_{min }(2)}=frac{t(cos 37}{theta sin 37}=frac{4}{3}=14: 3right) )