Question

From a point on the group at a distance 2 meters from the foot of a vertical wall , a ball is thrown at an angle 45∘ which just clear the top of the wall and afterwards strikes the ground at a distance 4 m on the other side. The height of the wall is

Answer 1

Using the equation of trajectory and applying for the point B(2,h)B(2,h) and also for the point C(6,0)C(6,0) we get,

h=2tan45∘−g(2)22v20cos245∘h=2tan⁡45∘−g(2)22v02cos2⁡45∘------(i)

0=6tan45∘0=6tan⁡45∘−g(6)22v20cos245∘−g(6)22v02cos2⁡45∘-----(ii)

Putting the value of g2v902cos245∘g2v902cos2⁡45∘from (ii) and (i) we

h=2−16h=2−16(2)2=43(2)2=43m

Answer 2

Explanation:

this is the correct answer