How do I calculate physics formulas containing derivatives and real numbers?

In summary, the conversation discusses calculating physics problems involving derivatives and real numbers. It mentions using the formula dP/dt = Fnet to calculate impulse, and the concept of taking a calculus course to better understand these calculations. It also mentions the importance of considering infinitesimal time intervals and the role of the Calculus in solving complex problems.
  • #1
NODARman
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Homework Statement
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Relevant Equations
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Hi, I'm trying to calculate my own physics problem but didn't get it something.
When I'm trying to calculate the impulse of the object when it's hit by F=10N force in the smallest possible time, then should I write:
dP/dt = Fnet => dP = Fnet*dt ?

Another question: In general, if I calculate just a net force, we know that the derivative of the constant is zero. Then if dP is 10 N/s and t->0 therefore Fnet = 10/0 ?
What I don't get is how to calculate any physics formula which contains derivatives and real numbers.
 
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  • #2
I don’t think any collision actually lasts 0 seconds. A collision that lasts 0 seconds is a collision that doesn’t actually happen.

Also ##dP## would have units of ##N \cdot s## not ##\frac{N}{s}##.
 
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  • #3
1664705379921.png

1664705400972.png

These might help

and if ##\dfrac{\mathrm{d}p}{\mathrm{d}t} = F(t)## then ## \displaystyle \Delta p = \int_{t_1}^{t_2}F(t) \mathrm{d}t##
Now one can define the average constant force of impulse as ##<F> = \Delta p / \Delta t = \Delta p / (t_2 - t_1) ##
i.e. ## \displaystyle <F> = \dfrac{1}{t_2 - t_1} \int_{t_1}^{t_2}F(t) \mathrm{d}t## which you might remember from calculus class.
 
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  • #4
NODARman said:
What I don't get is how to calculate any physics formula which contains derivatives and real numbers.
You could take a calculus course?
 
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  • #5
NODARman said:
When I'm trying to calculate the impulse of the object when it's hit by F=10N force in the smallest possible time
There's no such thing as the smallest amount of time. Unless you mean zero, in which case no collision occurs. The collision must last for some nonzero amount of time, however small.
 
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  • #6
NODARman said:
Homework Statement:: .
Relevant Equations:: .

What I don't get is how to calculate any physics formula which contains derivatives and real numbers.
You should not feel bad, it took a fellow named Newton to figure out how to deal with instantaneous change.
To any degree of approximation for a well behaved force, slicing time into finite intervals Δt, assuming the force is constant over that interval and summing will get you a numerical result to nearly any level of accuracy required.
But doing the clever stuff like calculating exact orbits for all time requires a leap of intuition. What happens to this rate of change as I slice time into infinitesimal pieces (dt) ?? The answer is called The Calculus and it is a touchstone for human ingenuity. It is not easy.
 
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1. What is a derivative in physics?

A derivative in physics is a mathematical concept used to describe the rate of change of a physical quantity with respect to another quantity. It is essentially the slope of a graph at a specific point and can be used to analyze how a physical system is changing over time.

2. How are derivatives used in physics?

Derivatives are used in physics to describe various physical quantities such as position, velocity, acceleration, and force. They can also be used to model and predict the behavior of physical systems, as well as to analyze the relationships between different physical quantities.

3. What is the difference between a first derivative and a second derivative in physics?

A first derivative in physics represents the rate of change of a physical quantity with respect to another quantity, while a second derivative represents the rate of change of the first derivative. In other words, the second derivative describes how the rate of change is changing.

4. Can derivatives be applied to all physical systems?

Yes, derivatives can be applied to all physical systems as long as there is a relationship between two quantities that can be described by a mathematical function. This includes classical mechanics, electromagnetism, thermodynamics, and quantum mechanics.

5. How do I calculate a derivative in physics?

To calculate a derivative in physics, you can use the standard rules of differentiation, such as the power rule, product rule, and chain rule. It is also helpful to have a good understanding of the physical meaning behind the mathematical equations and how they relate to the physical system being studied.

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