Question

A bullet is fired from a gun on the top of a building of height 1000 m at an angle of 30 .If the muscle speed of bullet is 80 m/s. Find the horizontal distance traveled by the bullet , When it reaches the ground .

Answer 1

Answer:

Horizontal range of bullet is 30 m.

Using range formula, R=

g

u

2

sin2θ

=30

or sin2θ=

(100)

2

30×10

orsin2θ=0.03

For small θ,sinθ=θ=tanθ,i.e.,2θ=0.03

Therefore, θ=0.015 rad

In ΔOAP,tanθ=

OP

AP

⇒AP=OPtanθ

The rifle must be aimed at an angle θ=0.015 above horizontal.

Height to be aimed = 30tanθ=30(θ)=30×0.015=45cm