Acceleration After Applied Force is Stopped?

AI Thread Summary
When a truck accelerates and then the clutch is engaged, the engine's force ceases, leading to a question about the subsequent behavior of acceleration and speed. The initial acceleration may not drop instantaneously to zero; instead, it decreases gradually, allowing the truck to continue gaining speed momentarily. This phenomenon is influenced by the inertia of the vehicle, which can cause it to coast and slightly increase in speed before deceleration begins. The speedometer reflects a smoothed average of speed readings, which can create the illusion of continued acceleration. Understanding these dynamics clarifies why the truck can momentarily climb in speed even after the applied force is removed.
Guy
Messages
2
Reaction score
0
I have a question that has been puzzling me for a while.

When I drive my truck and accelerate hard until 25 mph then put the clutch into roll freely, the truck will climb a few more mph before beginning to slow down. This is on flat ground or even a slight uphill.

The way I see it is as follows. Say acceleration of the truck is 5 ft/s2 (random number). Once the clutch is in the force from the engine is now 0, and therefore acceleration should be 0 unless there is another force pushing the truck forward. However in order to be continuous, acceleration cannot jump from 5 to 0, and will have to decrease continuously. While it is decreasing it is still positive and will cause velocity to climb slowly.

Can anyone explain the physics behind this?
 
Physics news on Phys.org
I assume that you are watching the speedometer to determine whether you are speeding up or slowing down.

In order to smooth out the readings so that the needle (or the digits) do not vary wildly, the number that is displayed will be some kind of decaying average of the most recent measured values.

As long as your current speed is still higher than the currently displayed average, that average will still be going up.
 
So its is not continuing to accelerate. Thanks for the answer that has bothered me for a while now!
 

Thread 'Is calling fictitious forces "not real" just about terminology?'

Hi there, im studying nanoscience at the university in Basel. Today I looked at the topic of intertial and non-inertial reference frames and the existence of fictitious forces. I understand that you call forces real in physics if they appear in interplay. Meaning that a force is real when there is the "actio" partner to the "reactio" partner. If this condition is not satisfied the force is not real. I also understand that if you specifically look at non-inertial reference frames you can...
View full post »

Thread 'Derivation of Hamilton's Principle: Questions'

I have recently been really interested in the derivation of Hamiltons Principle. On my research I found that with the term ##m \cdot \frac{d}{dt} (\frac{dr}{dt} \cdot \delta r) = 0## (1) one may derivate ##\delta \int (T - V) dt = 0## (2). The derivation itself I understood quiet good, but what I don't understand is where the equation (1) came from, because in my research it was just given and not derived from anywhere. Does anybody know where (1) comes from or why from it the...
View full post »

Similar threads

B Why doesn't a body accelerate upward when a force is applied?
Replies
7
Views
1K
Friction force has different effect than Applied Force?
Replies
9
Views
2K
Change in acceleration with change of angle of applied force
Replies
4
Views
2K
B Why Does a Spring Return to Its Original Position After Being Stretched?
Replies
9
Views
2K
Is a car's top speed the same on a wet road?
Replies
26
Views
7K
Physics of bullet impacts, I wonder if anyone can help?
Replies
17
Views
3K
How is force applied? Is resistance or load necessary for force to exist?
Replies
7
Views
2K
Determine if a car can pop a wheelie?
Replies
15
Views
3K
Accelerating a moving object with force
Replies
3
Views
2K
Force, linear and angular acceleration, car & wheels help
Replies
2
Views
4K

Hot Threads

Recent Insights

Back
Top