Register to reply

Acceleration After Applied Force is Stopped?

Share this thread:
May16-14, 09:24 AM
P: 2
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 in to 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?
Phys.Org News Partner Physics news on
Symphony of nanoplasmonic and optical resonators produces laser-like light emission
Do we live in a 2-D hologram? New Fermilab experiment will test the nature of the universe
Duality principle is 'safe and sound': Researchers clear up apparent violation of wave-particle duality
May16-14, 10:33 AM
P: 949
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.
May16-14, 12:16 PM
P: 2
So its is not continuing to accelerate. Thanks for the answer that has bothered me for a while now!

Register to reply

Related Discussions
Finding out applied force in order to get acceleration Introductory Physics Homework 4
Atwoods - applied force - reduced acceleration Introductory Physics Homework 6
Calculate acceleration of object with applied force and friction Introductory Physics Homework 2
Finding force of friction with only applied force and acceleration given? Introductory Physics Homework 1
Finding Acceleration from Friction Coefficient and Force Applied Introductory Physics Homework 6