Really TRUE odd factoids

[markemark]

Question - is it possible to instantaneously reverse your direction of travel? Will there always be a slowing down period, a period of rest then a period of acceleration in the opposite direction?

Instant change in velocity would infinite acceleration and as such impossible as any object with mass would require and infinite force to do so.

Now, objects without mass would be something to think about.

 

[Punkawallah]

Instant change in velocity would infinite acceleration and as such impossible as any object with mass would require and infinite force to do so.

Now, objects without mass would be something to think about.

It’s cheating, but if you drive at 30mph, and shoot a ball to your rear at 30mph, it stops and falls to the ground.

 

[markemark]

It’s cheating, but if you drive at 30mph, and shoot a ball to your rear at 30mph, it stops and falls to the ground.

The ball deccelerates on shooting based on the power of the gun from 30 to 0 over a period of time. It’s not instantaneous.

 

[Punkawallah]

The ball deccelerates on shooting based on the power of the gun from 30 to 0 over a period of time. It’s not instantaneous.

Hence ‘it’s cheating’.

 

[markemark]

Hence ‘it’s cheating’.

A ball decelerating from 30 to 0 is the same as acceleration from 0 to 30. It’s not cheating. It’s just wrong.

 

[Punkawallah]

A ball decelerating from 30 to 0 is the same as acceleration from 0 to 30. It’s not cheating. It’s just wrong.

I know. Cheating is wrong.

 

[markemark]

I know. Cheating is wrong.

So is not understanding physics.

 

[Joey Shabadoo]

So a fly flying at 0.2 mph hits a train doing 100mph in the opposite direction. The fly decelerates from 0.2mph to 0 then accelerates to 100mph. For a period of time, the fly is stationary so it's logical to deduce that the train has to be stationary at that point too - no?

 

[Asa Post]

So a fly flying at 0.2 mph hits a train doing 100mph in the opposite direction. The fly decelerates from 0.2mph to 0 then accelerates to 100mph. For a period of time, the fly is stationary so it's logical to deduce that the train has to be stationary at that point too - no?

Stationary, relative to what?

 

[Chris S]

So a fly flying at 0.2 mph hits a train doing 100mph in the opposite direction. The fly decelerates from 0.2mph to 0 then accelerates to 100mph. For a period of time, the fly is stationary so it's logical to deduce that the train has to be stationary at that point too - no?

Can the mass of a fly stop a train?

 

[classic33]

 

[Punkawallah]

So is not understanding physics.

‘Are you here for the five minute argument, or the ten?’

 

[DaveReading]

So is not understanding physics.

In this case, quantum physics.

There's no point in expecting to solve the problem simply using mechanics.

 

[Joey Shabadoo]

Stationary, relative to what?

Relative to an outside observer

 

[matticus]

So a fly flying at 0.2 mph hits a train doing 100mph in the opposite direction. The fly decelerates from 0.2mph to 0 then accelerates to 100mph. For a period of time, the fly is stationary so it's logical to deduce that the train has to be stationary at that point too - no?

Are the fly and the train inelastic bodies? Point masses?