Question

a bird is sitting on the top of 80m high tree from a point on the ground the angle of elevation of the bird is 45 the bird flies away horizontally in such a way that it remain at a constant height from the ground affer 2 sec the angle of elivation from the same point is 30 degree find the speed of flying bird

Answer 1

Answer:

tan45o=BCAC

1=BC80

BC=80cm

tan30o=BC+CEDE

31=80+x80

80+x=803

x=803−80

x=80(3−1)m

The bird travelled 80(3−1)m

Speed of bird =TimeDistance

=240(3−1)

=40(3−1)m/s

∴ Speed =40(3−1)m/s,