Mechanics

IB Physics: Mechanics

IB Physics: Mechanics

Florian Spiess

Florian Spiess

Kartei Details

Karten 12
Sprache English
Kategorie Physik
Stufe Andere
Erstellt / Aktualisiert 18.04.2013 / 01.08.2017
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Define Average Velocity.

The total displacement of the object in the total time:

Velocity (Vav) = total displacement (s) / total time (t)

Define Instantaneous Velocity.

The velocity at any one instant:

v = Δs / Δt

Where Δt is tending towards zero

v = ds / dt

velocity is the derivative of displacement with regards to time

What does the slope on a displacement-time graph represent?

velocity

What does the slope on a velocity-time graph represent?

acceleration

What does the area under a velocity-time graph represent?

displacement

What does the area under an acceleration-time graph represent?

velocity

How many equations of uniformly accelerated motion are there?

What is the first suvat equation, which is concerned with finding acceleration or velocity?

a = change of velocity / time taken

a = final velocity (v) - initial velocity (u) / time (t)

therefore: v = u + at

What is the second suvat equation, which is concerned with finding displacement without use of acceleration?

Since: average velocity = initial velocity (u) + final velcoity (v) / 2

and: average velocity = displacement (s) / time (t)

s / t = u +v / 2

Therefore: s = 1/2 (u + v) t

What is the third suvat equation, which is concerned with finding displacement without the use of final velocity?

Since: final velocity = initial velocity + acceleration * time

v = u + at

Hence: s = 1/2 (u + u + at) t

and: s = ut + 1/2 at2

What is the fourth suvat equation, which is concerned with finding final velocity without the use of time?

Eliminate t from suvat equation 3 by substituting:

t = (v - u) / a

which can be derived from suvat equation 1 to make:

v2 = u2 + 2as

When are the suvat equations useful?

When three or four of s, u, v, a or t are known and the others need to be found.