Question

A hunter points a rifle horizontally and holds it 3.30 m above the ground. The bullet leaves the barrel at 325 m/s and experiences no significant air resistance. The acceleration due to gravity at this location is 9.80 m/s2. How long does it take for the bullet to strike the ground? To the nearest tenth of a second like 0.x S

Answer 1

Answer:

0.8 seconds

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

g = Acceleration due to gravity = 9.81 m/s²

In the y axis

From the equations of motion we have

$v^2-u^2=2gs\\\Rightarrow v=\sqrt{2gs+u^2}\\\Rightarrow v=\sqrt{2\times 9.8\times 3.3+0^2}\\\Rightarrow v=8.04238\ m/s$

$v=u+gt\\\Rightarrow t=\dfrac{v-u}{g}\\\Rightarrow t=\dfrac{8.04238-0}{9.8}\\\Rightarrow t=0.82065\ s$

It takes 0.8 seconds to strike the ground