Why can't we apply the speed equation in a free fall?

AI Thread Summary
In free fall, acceleration is constant at 9.8 m/s², causing velocity to increase continuously. The formula Speed = D/T can be used to calculate average speed over a time interval, but it does not account for changing velocity at specific moments. This average speed represents the total distance divided by total time, reflecting the overall motion rather than instantaneous speed. For precise velocity at any given point, kinematic equations are necessary. Understanding these distinctions is crucial for accurate physics calculations.
axer
Messages
35
Reaction score
4
Hello, so i know in a free fall the acceleration is constant (9.8 m/s2) therefore speed/velocity is increasing.. But I am wondering why we can't use Speed=D/T
 
Physics news on Phys.org
Go back and think about the several points you just made. If velocity is changing, does a formula that gives a single speed over time make sense to you.
 
axer said:
Hello, so i know in a free fall the acceleration is constant (9.8 m/s2) therefore speed/velocity is increasing.. But I am wondering why we can't use Speed=D/T

You can and that will give you the average speed.
 
axer said:
Hello, so i know in a free fall the acceleration is constant (9.8 m/s2) therefore speed/velocity is increasing.. But I am wondering why we can't use Speed=D/T
You most definitely can use the velocity = d/t formula. Just keep in mind that the speed you will find from this equation will be the average velocity, this means that it is the average of all the velocities combined since you are combining the total distance and total time.

If you want to find the velocity at any given point in time or space, then you need to use the kinematic equations.
 

Thread '1:1 versus 2:1 Mechanical Advantage debate'

The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
View full post »

Thread 'Newton's first law?'

Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
View full post »
Thread 'Beam on an inclined plane'

Thread 'Beam on an inclined plane'

Hello! I have a question regarding a beam on an inclined plane. I was considering a beam resting on two supports attached to an inclined plane. I was almost sure that the lower support must be more loaded. My imagination about this problem is shown in the picture below. Here is how I wrote the condition of equilibrium forces: $$ \begin{cases} F_{g\parallel}=F_{t1}+F_{t2}, \\ F_{g\perp}=F_{r1}+F_{r2} \end{cases}. $$ On the other hand...
View full post »

Similar threads

B Help me understand jerk of a falling object hitting an "ideal foam"
Replies
7
Views
1K
I How to Land a Tree Flat in 3/4 Rotation: Solving the Equations
Replies
19
Views
2K
Free fall equations with realistic, altitude-dependent g?
Replies
13
Views
3K
Free fall detect of rotating object
Replies
10
Views
3K
Equations for a mass falling to Earth from a distance
Replies
3
Views
2K
Can a bullet hit someone while free falling?
Replies
7
Views
2K
Free fall does'nt consider weight
Replies
2
Views
2K
I Apparent Weight problem (falling beam)
Replies
2
Views
2K
I A rod that falls while rotating from the end of a table
Replies
2
Views
1K
Time for Free Fall from Great Distances
Replies
2
Views
1K

Hot Threads

Recent Insights

Back
Top