Kinematics of motion in a straight line flashcards

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What do the letters in SUVAT stand for?

s: displacement, u: initial velocity, v: final velocity, a: acceleration, t: time.

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What is the crucial condition for using the SUVAT equations?

Acceleration must be constant. If acceleration is given as a function of time (e.g., a = 2t), you must use calculus.

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What does the gradient of a displacement-time (s-t) graph represent?

Velocity. A straight line means constant velocity; a curve means changing velocity (acceleration).

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What does the gradient of a velocity-time (v-t) graph represent?

Acceleration. A horizontal line means zero acceleration (constant velocity).

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What does the area under a velocity-time (v-t) graph represent?

Displacement. To find total distance travelled, you must add the areas, treating any area below the t-axis as positive.

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What is the difference between displacement and distance?

Displacement is a vector quantity (how far from the start point, including direction). Distance is a scalar quantity (how far you've travelled in total).

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What is the equation linking v, u, a, and t?

$v = u + at$

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What is the SUVAT equation that does not involve time, t?

$v^2 = u^2 + 2as$

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How are velocity (v) and displacement (s) related using calculus?

Velocity is the rate of change of displacement: $v = \frac{ds}{dt}$. To find displacement from velocity, you integrate: $s = \int v \, dt$.

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How are acceleration (a) and velocity (v) related using calculus?

Acceleration is the rate of change of velocity: $a = \frac{dv}{dt}$. To find velocity from acceleration, you integrate: $v = \int a \, dt$.

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What value is used for acceleration 'a' in vertical motion problems (free fall)?

$a = g \approx 9.8 \text{ m s}^{-2}$ (or sometimes 10). Its sign depends on your chosen positive direction (e.g., if up is positive, $a = -9.8$).

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A particle starts from rest. What does this imply?

The initial velocity, $u$, is 0.