Question

A parachute is tied to a stone (A). Initially a man was seated on the parachute when it made ${60}^{\circ }$ with the horizontal plane. After sometime the man ties the rope to himself and then jumps off from the parachute. At some point C man makes ${30}^{\circ }$ with the horizontal plane. From B, an imaginary line is drawn perpendicular to the ground so that it cuts AC (in the fig) in D. Distance BD is……………………………m

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Answer 1

Height of B from ground =20 $\times$ $\sin$ ${60}^{\circ }$

Height of C from ground=20 $\times$ $\sin$ ${30}^{\circ }$

Therefore, Vertical distance BC=20 ($\sin$ ${60}^{\circ }$ - $\sin$ ${30}^{\circ }$)

=10(1.732-1)

=7.32m