Projectile word problem..Is my answer correct?

Question

A rifle is aimed horizontally at a target 57 m away. The bullet hits the target 2.3 cm below the aim point.

 

A) What is the flight time of the bullet and b) What is the velocity when the rifle shoots?

 

For a) I got 0.069s and b) 830 m/s 

Answer 1

Hi Kyle,

 

You must be rounding to 2 sigfigs  but you have the correst answers. Since the bullet was fired horizontally, the vertical velocity, v_o = 0.

 

0.023m = (1/2)(9.8m/s²)t²

(0.023m)/(4.9m/s²) = t²

0.0685 s = t

 

 

57 m / 0.069 s = 826 m/s