# Homework Help: A bet falling objects

1. Jun 20, 2010

### davidco2

One of us said:

A metal ball and wooden ball regardless of weight and radius will hit the ground at the same time when dropped from any height (building)

Second thing...
is the speed of bullet exiting the barrel pointing upwards the same as it's speed when it hits the ground?

2. Jun 20, 2010

### Staff: Mentor

Answers depend on whether you ignore drag or not.

3. Jun 20, 2010

### davidco2

it is not in vacuum... a real life situation with all influences included

4. Jun 21, 2010

### Staff: Mentor

5. Jun 21, 2010

### davidco2

I just say billiard ball and a wooden ball with radius of 20m will not hit the ground at the same time, if dropped from 100m building (fall time will depend on size and weight of the object)
and also
bullet exiting barrel pointing 90degree upwards has the same speed as in moment hitting the ground (same level as gun)
Am I right or wrong ?

6. Jun 21, 2010

### Staff: Mentor

Yes, no.

Falling objects - if falling for long enough - usually obtain some maximal speed, which is a function of mass & drag. Initial speed of the bullet doesn't matter much, as long as the bullet got high enough.

7. Jun 23, 2010

### davidco2

So it is YES that glass marble and cannonball will hit the ground at different moments?

8. Jun 23, 2010

### Staff: Mentor

Difference will be very small, but as they differ in density - yes, that's what we should expect.