# 2d kinematic problem

## Homework Statement

A large very powerful gun shoots a bullet that easily goes through a block. In the process the block is knocked off the post and falls to the ground. Which hits the ground first, the bullet or the block. Why?

## The Attempt at a Solution

I am thinking that the block would fall to the ground faster because it has a zero x component of velocity, but i'm not sure if this is true.

## Answers and Replies

BiGyElLoWhAt
Gold Member
Let me give you a new problem that might help you see this problem in new light.

2 blocks are floating in space at lets say x= 0m y= 5m (they are separated on the z axis, but they won't change their z coordinates so we can ignore them, but they're not at the same point in space is what I'm getting at). We will use standard 2d coordinates, x is left and right, y is up and down. At some time I hit both blocks and they instantaneously acquire their (constant) velocities. Let's say block A moves with a velocity <5, -1> and block B moves with a velocity <0, -1> which one hits the ground first?

Now, same initial situation, but this time they're going to accelerate. When I hit the blocks block A moves at
<10 , -9.8t> and block B moves at <10 , -10t>. Now which one hit's the ground first?