Deriving Big 5 Motion Laws Non-Calculus and Calculus

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In summary, the conversation discusses various methods for deriving the big 5 motion laws, including both calculus and non-calculus approaches. The laws discussed include dv=adt, dx=vdt, dx=v0dt, and vavg=xt. The conversation also mentions the last law, deltav^2=2ax, which has stumped the speaker. They have partially solved it using calculus, but are still seeking a non-calculus explanation.
  • #1
quincyboy7
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"Simple" derivations

I set out trying to derive the big 5 motion laws not only regularly, but calculus-style:

dv=adt
Integration yields v=at + C, and thus we get v=at+v0.
Non-calculus method is just using the definition of a=deltav/deltat and is trivial.

dx=vdt
x=(v0+at)dt
x=v0t + 1/2at^2 + C, and thus x=v0t + 1/2 at^2 + x0.

dx=v0dt
x=(v-at)dt
x=vt-1/2at^2+C, and thus x=vt-1/2at^2 + x0.

vavg=xt, and vavg=(v0+v)/2...i get that because of simple math and graphing with constant acceleration, but is there a calculus way to prove this?

What are the non-calculus derivations for the two i just mentione above.
Also, the last one has completely stumped me...(deltav^2=2ax), both non-calculus and calculus methods. If you have any hints/derivations with which to enlighten me, that would be much appreciated. Thanks.
 
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  • #2


quincyboy7 said:
I set out trying to derive the big 5 motion laws not only regularly, but calculus-style:

dv=adt
Integration yields v=at + C, and thus we get v=at+v0.
Non-calculus method is just using the definition of a=deltav/deltat and is trivial.

dx=vdt
x=(v0+at)dt
x=v0t + 1/2at^2 + C, and thus x=v0t + 1/2 at^2 + x0.

dx=v0dt
x=(v-at)dt
x=vt-1/2at^2+C, and thus x=vt-1/2at^2 + x0.

vavg=xt, and vavg=(v0+v)/2...i get that because of simple math and graphing with constant acceleration, but is there a calculus way to prove this?

What are the non-calculus derivations for the two i just mentioned above.
Also, the last one has completely stumped me...(deltav^2=2ax), both non-calculus and calculus methods. If you have any hints/derivations with which to enlighten me, that would be much appreciated. Thanks.

Somewhat solved. a=dv/dt=(dv/dx)(dx/dt)=vdv/dx. Then adx=vdv and ax=v^2/2 + C and so the show goes on. Wicked relieved, but still would appreciate any calculus answers to why vavg=1/2 (v0+v) and a non-calculus answer to the last rule still.
 

Related to Deriving Big 5 Motion Laws Non-Calculus and Calculus

1. What are the Big 5 motion laws?

The Big 5 motion laws, also known as the kinematic equations, are a set of equations that describe the motion of an object in terms of its initial velocity, final velocity, acceleration, displacement, and time. These equations are used to solve problems involving motion without the use of calculus.

2. How do you derive the Big 5 motion laws without calculus?

The Big 5 motion laws can be derived using basic algebra and the principles of motion. By considering the definitions of velocity and acceleration, and using the equations of motion, it is possible to manipulate the equations to arrive at the Big 5 motion laws.

3. Can the Big 5 motion laws be derived using calculus?

Yes, the Big 5 motion laws can also be derived using calculus, specifically using the principles of differentiation and integration. This approach is more mathematically rigorous and can handle more complex situations, but it is not necessary for solving basic motion problems.

4. What are the advantages of using the Big 5 motion laws over calculus?

The Big 5 motion laws are simpler and more intuitive than using calculus, making them more accessible for students and non-mathematicians. They also do not require an understanding of derivatives or integrals, making them easier to use for basic motion problems.

5. Can the Big 5 motion laws be used for all types of motion?

The Big 5 motion laws are most accurate for motion that is constant, or changing at a constant rate. For more complex motion, such as non-uniform acceleration, calculus may be necessary. However, the Big 5 motion laws can still provide a good approximation in these situations.

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