How long before the box hits the ground?

  • Thread starter Thread starter unidentified4789
  • Start date Start date
Click For Summary
A plane traveling at 100 m/s drops a box from an elevation of 2000 meters. Assuming no air resistance, the box's fall is governed by the equation for freefall, where the acceleration due to gravity is 9.8 m/s². The time to reach the ground can be calculated using the formula 4.9t² = 2000, leading to a specific time for the fall. The horizontal speed of the plane does not affect the time it takes for the box to hit the ground, as the fall is determined solely by vertical motion. The discussion clarifies the importance of focusing on vertical acceleration rather than horizontal displacement.
unidentified4789
A plane is traveling at 100m/s when it drops a box at an elevation of 2000 meters. How much time is required for the box to reach the earth?
 
Physics news on Phys.org
You know the equation for freefall? Apply it to find the time and multiply the time by the speed of the plane.
 
What assumptions are you making? Are you ignoring air resistance? (If not, then you will have to state what the air resistance is.)

Assuming no air resistance, 2000 m is low enough that we can ignore the change in gravitational force due to change in distance so: the acceleration is 9.8 m/s2. The downward speed after time t is 9.8 t m/s and the distance fallen is 4.9 t2. The box will hit the Earth when 4.9 t2= 2000.

The information about the horizontal speed of the airplane (and therefore the horizontal speed of the box) is irrelevant. The time to hit depends only on vertical acceleration and speed.
 
As someone informed me in a pm, I misread the problem. Sorry. Halls had it right. I was thinking of how far the box would move forward.
 

Thread 'Does acceleration affect impact energy vs constant velocity?'

I do not have a good working knowledge of physics yet. I tried to piece this together but after researching this, I couldn’t figure out the correct laws of physics to combine to develop a formula to answer this question. Ex. 1 - A moving object impacts a static object at a constant velocity. Ex. 2 - A moving object impacts a static object at the same velocity but is accelerating at the moment of impact. Assuming the mass of the objects is the same and the velocity at the moment of impact...
View full post »

Similar threads

Undergrad How Do ICBMs Accurately Reach Their Targets?
  • · Replies 13 ·
Replies
13
Views
6K
Undergrad Dropped objects hitting the ground at the same time?
  • · Replies 41 ·
2
Replies
41
Views
8K
Undergrad Photon in a mirrored box moving in direction of travel
  • · Replies 26 ·
Replies
26
Views
2K
MHB Mass 50kg Box Slows to Halt on Friction: 14.5m Distance
  • · Replies 4 ·
Replies
4
Views
1K
MHB Calculate the Length & Potential Energy of a Sliding Box on a Ramp
  • · Replies 9 ·
Replies
9
Views
2K
Undergrad How was the speed of light calculated before the redefinition of the meter?
  • · Replies 8 ·
Replies
8
Views
4K
High School What is the Gs of an object hitting the ground at 31 mph?
  • · Replies 14 ·
Replies
14
Views
2K
Egg Drop Project: Prepping the Container for a Successful Fall
  • · Replies 4 ·
Replies
4
Views
4K
How Long for a Beam of Light to Reach Earth?
  • · Replies 21 ·
Replies
21
Views
2K
Would the delay cause the box to move?
  • · Replies 20 ·
Replies
20
Views
4K