Question

An object that is fired horizontally hits the ground in 0.500 seconds. If it had been fired with twice the speed, but still horizontally, it would have hit the ground in

Answer choices:

A) Less than 0.500s
B) More than 0.500s
C) 0.500s
D) Not enough Information

Answer 1

The answer is (C), 0.500s.

This is because in both instances the bullet is fired with all horizontal speed, meaning the initial vertical component of velocity (
`\vec v_(y)`) will equal 0. We also know that vertical acceleration (
`\vec a_(y)`) is the acceleration of gravity, which is 9.8 m/s^2. In both cases when the bullet is fired, the acceleration of gravity will pull them down in the same way. Thus, the time the bullet takes to hit the ground will be the same.

In short, because the velocity and acceleration is constant in the vertical direction, the bullets will fall in the same amount of time.