Question

John shot a bullet from his rifle with a speed of 650 m/s. How much time is needed for the bullet to strike a target 3900 m away?

a) 6 seconds
b) 10 seconds
c) 15 seconds
d) 6.5 seconds

Answer 1

The time needed for a bullet traveling at 650 m/s to hit a target 3900 m away is 6 seconds.

Step-by-step explanation:

To find the time it takes for the bullet to strike the target, you can use the kinematic equation:

Distance = Initial velocity * Time + 1/2*Acceleration*Time^2.

Since the bullet is only affected by gravity vertically and not horizontally, the horizontal acceleration is zero a_x = 0. Therefore, the equation simplifies to:

Distance = Initial velocity/Time

Rearrange the equation to solve for time t:

Time = Distance/Initial velocity.

Plug in the given values:

Time = 3900m/650 m/s

Time = 6s.

Therefore, the correct answer is:

a) 6 seconds

This is the time needed for the bullet to strike a target 3900 m away at a speed of 650 m/s.