Organizing Physics Formulas for Assignment: Maximizing Marks

In summary, the best way to set out your physics assignment is by using formulas such as f=m*a and a=(v-u)/t. Additionally, you will need to understand how to calculate drag and power, as well as understand how a car can reach its maximum speed before hitting the traps.
  • #1
hazakate
8
0
i have a few formula for my physics assignment but i want to know the best way to set it out and what other formula i can use.

i already have the formula f=m*a and a=(v-u)/t.
i just really need the marks
 
Physics news on Phys.org
  • #2
Perhaps if you described what the assignment requires we would be of more help? You probably need a good grasp of mechanics, and that includes the formulas you list as well as some more. Here are just a few:

[tex]x(t) = x_0 + v_0t + \frac{1}{2}at^2[/tex]
[tex]v(t) = v_0 + at[/tex]
[tex]v = \frac{dx}{dt}[/tex]
[tex]a = \frac{dv}{dt}[/tex]
[tex]\Sigma F = ma[/tex]

This might also be helpful:
http://hyperphysics.phy-astr.gsu.edu/hbase/mot.html#motcon
 
  • #3
s = ut + 1/2 a t^2

For drag racing, u is zero. s is 1/4 mile (usually) (402.336 metres) so you get

402.336 = a/2 * t^2

t = sqrt(804.672 / a)

So you see that 1g (g = 9.81) acceleration will give you a 9 second run
or 5g would give a 4 second run

Real dragsters don't accelerate at a constant rate, but these formulae are ok as approximations.
 
  • #4
You assume that the car accelerates not only constantly, but also throughout the race. Who's to say the car doesn't top at some value of V and proceeds with no acceleration at all?
 
  • #5
Usually, car is first traction-limited, in which case, applied force F is constant:
[tex]mdv/dt=F-Cv^2[/tex]
At some point, it becomes power -limited with P constant:
[tex]mdv/dt=P/v-Cv^2[/tex]
C is aerodynamic drag coefficient. Aero drag is much more important than rolling resistance, so I ignore a [itex]C_2v[/itex] term.
BTW, you will notice that C can be derived from top speed [itex]v_\infty[/itex] (where dv/dt=0):
[tex]C=P/v_\infty^3[/tex]
 
Last edited:
  • #6
thank you this helps
 
  • #7
Chen said:
You assume that the car accelerates not only constantly, but also throughout the race. Who's to say the car doesn't top at some value of V and proceeds with no acceleration at all?

when that happens you
A shift a gear
or if in top gear

B change final drive gears

but very few cars will do that in top gear
ie reach top speed in less than a 1/4 mile
 
  • #8
ray b has it. If the car reaches maximum speed before it hits the traps, the mechanics will work the car over by changing the gears in the rear-end.
 

1. How can I effectively organize my physics formulas for assignments?

To effectively organize your physics formulas for assignments, it is important to first understand the different formulas and their relationships. You can group similar formulas together, such as those related to motion or energy. Additionally, you can create a table or chart to visually organize the formulas and their variables. It may also be helpful to label and color-code the formulas for easier identification.

2. Should I write out all the formulas or just the final answer?

It is generally recommended to write out all the formulas used in your assignment, as this shows your understanding of the concepts and the process you used to arrive at the final answer. However, if the instructions specifically state to only provide the final answer, then you can omit the formulas.

3. How can I remember all the physics formulas?

One helpful way to remember physics formulas is to practice regularly and consistently. You can also create flashcards or study guides with the formulas and their explanations. Additionally, understanding the concepts and relationships between formulas can also aid in remembering them.

4. Can I use abbreviations or symbols for formulas in my assignment?

It is generally recommended to use the full and correct format of the formulas in your assignment. However, if you are limited on space or time, you can use abbreviations or symbols as long as they are clear and understandable. It is important to check with your instructor beforehand if abbreviations or symbols are allowed.

5. What should I do if I am unsure which formula to use for a specific problem?

If you are unsure which formula to use for a specific problem, you can start by identifying the given information and the desired unknown. Then, refer to your notes or textbook to find a relevant formula. If you are still unsure, you can ask your instructor for clarification or seek help from a classmate or tutor.

Similar threads

Replies
3
Views
667
Replies
5
Views
2K
Replies
3
Views
4K
Replies
13
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
269
Replies
16
Views
470
Replies
17
Views
884
  • Mechanics
Replies
1
Views
489
Replies
4
Views
2K
Replies
9
Views
2K
Back
Top