Question

From the top of tower of height 80m, two stones are projected horizontally with velocities 20m/s and 30m/s in opposite directions. The distance between both the stones on reaching the ground is x * 10 m, where x is

Answer 1

Thus, question is related to Projectile motion and in this question we will use formula of Horizontal Range i.e.

Let , distance between them = D = 10x

R = u√2h/g

In first case when velocity is 20 ms-¹ and height is 80 m.

R = u√2h/g

R = 20 √2×80/10

R = 20 × √16

R = 20 × 4

R = 80 m

In second case when velocity is 30 ms-¹ and height is 80 m.

R' = u’√2h/g

R' = 30 √2×80/10

R' = 30 √16

R' = 30 × 4

R' = 120 m

Hence,

Distance between both the stones = D = R + R'

D = 80 + 120

D = 200 m

As we are given an equation that,

10x = 200 m

x = 200/10

x = 20 m

Hence, the above equation can be written like that,

D = x*10 = 20 × 10