Constant Acceleration

[Paul Arden]

So if we go from A to B with the rod at a steady (constant) acceleration, we have a different result than if we reach B at the same time, but had started slowly and then accelerated quickly at the end of the stroke to catch up. While the rod butt arrives at B at the same time with both strokes, the bend in the rod will be greater in the second scenario.

The question is how significant is this? And will it always cause a tail as some people (mistakenly I believe) think?

Cheers, Paul

[Graeme H]

That’s why we talk about application of power, not acceleration (force)

Power is a function of both acceleration and time, or put another way, it is when we apply the force.

(More correctly power is force multiplied by velocity, but velocity is displacement / time, so power is a function of force and time and distance)

[Merlin]

Lou

You are correct, there is just a question of definition covered by Stoaststail and Graeme. To me "distance" gave the idea of a location in space, hence my question.

Merlin

[Graeme H]

“Distance” implies a starting location. The space between two locations (displacement) is what we call call distance. But we also need to know which direction we’ve moved.

So distance is not location. It requires a relationship to a second location to be meaningful.

Cheers, Graeme

[Graeme H]

This got me thinking a bit more. According to Wikipedia:

In physics, jerk (also known as jolt) is the rate of change of an object's acceleration over time.

That’s something I don’t remember being taught at school.

[Stoatstail50]

So, without wishing to confuse the issue any more, or offer an alternative definition to the term Jerk

If my velocity is 1mps thataway and I travel for 100m thataway at 1mps or 1000m thataway at 1mps I think my velocity is still 1mps thataway. In order to calculate speed I may have displaced 1m or 0.00001 of a m or 10,000m. is this wrong ? I may need strong drink.

[Graeme H]

Sorry, I am actually confused by this.

Your speed is the distance you’ve travelled divided by the time it took to do it.

(Velocity has direction included too,)

[Stoatstail50]

My velocity is unchanged by the distance travelled.

[Graeme H]

Sorry. I should not have edited.

[Graeme H]

My velocity is unchanged by the distance travelled.

Well, yeah, if you travel at a constant velocity, your velocity stays the same regardless of how far you walked. That’s what a constant velocity means.

However, if you walk at 4 km/h for a km and then jog at 8km/h for 2 km in the same direction, your velocity for the total distance is 6 km/h. You travelled 3 km in half an hour. Displacement divided by time.

Cheers, Graeme