The Maths and Science Thread - Collection of Problems and Facts

[Varun]

A lot of heat?

 

[AbhishekS]

This is what I think regarding Akshay's question.

Sorry for spelling and grammatical errors. Realized today that typing in photoshop sucks.

 

[Dr. Pepper]

Basically I made a velocity-time graph for a "ball that gets thrown straight up in the air and is caught again". So it starts at the highest velocity and constantly decreases through v=0 into the negative velocity (as it comes back down) then back up to 0 again. I'm pretty sure this is right, but how do I use the graph to find the height that the ball reached?

Another question:

Someone can throw a ball and release it at 40m/s. It accelerates over a distance of 3.5m, what's the average acceleration?

I know it sounds as if I'm just asking you guys for answers to my homework all the time but I'm genuinely stuck and need help. For the 2nd one, would the initial velocity be 40m/s? And could you use that to do time=distance/velocity = 3.5/40=0.0875 seconds? And how would you work out the distance from that? I'm slightly put off by the average acceleration bit, how would that differ from normal acceleration?

 

[Varun]

It accelerates over a distance of 3.5m, what's the average acceleration?

Is that 'It accelerates uniformly over a distance of 3.5m' or not? I just want to confirm that.

 

[Dr. Pepper]

It doesn't really say. It says "accelerate the ball through a distance of 3.5m".

Dr. Pepper added 19 Minutes and 29 Seconds later...

I've figured that one out now.

v^2=u^2 + 2as
If u is 0 so it gets cancelled out
40^2 = 2 x a x 3.5
a= 228.57m/s^2

I've got a displacement(y axis)-time (x axis) graph and it makes a curve as you'd expect. But I need to draw a tangent at a certain point to work out the speed. I'm confused as what's meant by tangent.

 

[Varun]

This would help you.
Tangent - Wikipedia, the free encyclopedia

While I know what a tangent is, I am too lazy to explain it.

 

[Dr. Pepper]

Yeah I know the definition of a tangent, I just don't get how it would work on a graph.

 

[Kshitiz_Indian]

I think what you actually need is the slope of the graph, which can be calculated by calculating the derivative. You know what a derivative is?

 

[AbhishekS]

I think what you actually need is the slope of the graph, which can be calculated by calculating the derivative. You know what a derivative is?

Is it that dy/dx=slope?

 

[Kshitiz_Indian]

Is it that dy/dx=slope?

Yeah, where y is a function of X. Velocity is the slope of the displacement-time graph, and acceleration is the slop of velocity-time graph.

 

[Dr. Pepper]

I'm not sure I'm getting you. I just got what the displacement and time where at those points and did velocity=displacement x time.

 

[LegBreakGoogly]

Do Any of you know the maths surrounding quantum theory

 

[Varun]

You mean the quantum numbers?

 

[AkshayC]

approximately 45% in my opinion Mathematics is related to Quantum theory!!I know little bit about it.

 

[AkshayC]

can any one tall me:-
What happens when an irresistible force meets an immovable object?