Does Initial Velocity Affect Falling Objects' Time to Hit the Ground?

  • Context: Undergrad 
  • Thread starter Thread starter OpenIntro
  • Start date Start date
  • Tags Tags
    Gravity Theory
Click For Summary
SUMMARY

The discussion centers on the effects of initial velocity on the time it takes for falling objects to hit the ground. It is established that if two objects are dropped from the same height, they will land simultaneously in a vacuum with uniform gravitational conditions. However, if one object is shot horizontally, they will only hit the ground at the same time if air resistance is neglected and the projectile's angle is adjusted appropriately. The initial downward velocity of a projectile influences its descent, causing it to hit the ground sooner if shot downward, while a horizontal shot results in simultaneous landing with a dropped object.

PREREQUISITES
  • Understanding of basic physics concepts, particularly gravity and projectile motion.
  • Familiarity with the principles of uniform gravitational fields.
  • Knowledge of the effects of air resistance on falling objects.
  • Ability to apply kinematic equations in physics.
NEXT STEPS
  • Study the kinematic equations for projectile motion in physics.
  • Learn about the effects of air resistance on falling objects.
  • Explore the concept of gravitational fields and their uniformity.
  • Investigate the principles of motion in a vacuum versus atmospheric conditions.
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone interested in understanding the dynamics of falling objects and projectile motion under varying conditions.

OpenIntro
Messages
1
Reaction score
0
We have a debate going on here, and I am not fresh enough on my physics in order to explain the reason why I am right...I think...lol...

It's a question of gravity...

I know that if two objects are DROPPED at the same height, they will hit the ground at the same time. That's a given. The argument is, if an object is dropped from height x...and an object is, for argument's sake, shot from a gun...will they hit the ground at the same time? One has velocity, and the other doesn't. Does this make a difference?

If someone could explain this out with formulas, it would be much appreciated!
 
Physics news on Phys.org
They will reach the ground at the same time only if the one shot from a gun is fired horizontally in a UNIFORM gravitational field and in a vacuum! Since the Earth is round the gravitational field is not uniform and we have an atmosphere so the landing time will generally be different. Of course you may adjust the angle of the projectile (very slightly!) to force them to land at the same time.

In a uniform gravitational field and in a vacuum they will reach the ground at the same time when the bullet is fired horizontally because the horizontal and vertical motions of the projectiles are independent of each other.
 
Assuming all else is equal and neglecting the effects of air resitsnace, etc. (which shouldn't quakitvely effect the results): it depends on direction that the object is shot : if it is shot towards the ground (i.e. the compnoent of it's velocity downwards is positive) then it will indeed it the ground first. If it is shot parallel to the ground then the two objects will hit the ground at the same time and if it is shot away from the ground (i.e. the component of it's velocity downwards is negative) then it will hit the ground after the object that is simply dropped.

This si as the initial velocity downwards will help to determine the average velocity downwards.
 

Similar threads

High School The horizontal speed of an object does not affect the time it takes to fall vertically?
  • · Replies 22 ·
Replies
22
Views
3K
Undergrad How to Calculate force exerted on a falling body?
  • · Replies 12 ·
Replies
12
Views
3K
Undergrad How can I calculate the force of a falling object?
  • · Replies 26 ·
Replies
26
Views
10K
Undergrad Dropped objects hitting the ground at the same time?
  • · Replies 41 ·
2
Replies
41
Views
9K
Undergrad How Does the Angle at P1 Change Over Time Until the Object Falls?
  • · Replies 2 ·
Replies
2
Views
2K
High School Time to fall from 200 miles
  • · Replies 8 ·
Replies
8
Views
2K
High School Bullet Velocity Experiment: Does a Fired or Dropped Bullet Hit the Ground First?
  • · Replies 8 ·
Replies
8
Views
3K
Undergrad Help Needed with Tracker Physics Program Measuring Acceleration
  • · Replies 10 ·
Replies
10
Views
3K
High School How Does Liquid Density and Viscosity Influence Free Fall Braking?
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Newton's second law and pressure wave propagation
  • · Replies 27 ·
Replies
27
Views
3K