Mechanics - Frequent Mistakes Flashcards
What is the equation of the work energy principle?
Explain a bit?
Fs doesn’t include gravitational
After this scenario,
What do you know about W and V?
State the tip on proving A and B don’t collide?
After the collision W≥V (common physics sense)
V≥ as if v=0 there is no collision
When doing chapter 4 and 5 what is necessary to keep in mind?
There is no good law to calculate the speed of approach and speed of separation so be careful
What is the best way to show that something is positive?
Complete the square
What 2 things do you need to keep in mind with elastic springs and strings questions?
t or p
At equilibrium there will be EPE
When doing the vector method what do you need to remember?
After solving for a and b the magnitudes is ax the parallel vector etc not just a
What do you know about the speed of an object?
When did I make this mistake?
Speed will always be +
When i was working with algebra not numbers
What may be a shortcut if 2 objects are moving towards a wall to prove that there will be a second collision?
V>0
What may you forget when working out the range of e?
The close end bound (as 0≤e≤1)
How do you work out the fraction of Ke lost?
What do you need to remember o do when stating an angle or direction?
Say the angle from … the wall for example
1J = how many mJ?
1J = 1000mJ
General tip about GPE?
Remember that in very few questions GPE may be increasing 1 ay but decreasing in another (pully systems)
Why is this equation not fully true?
Explain fully?
State the impulse if it is // to i-j?
I = ai - bj
