phy_a11_quiz1

course PHY 201

Determine the acceleration of an object whose velocity is initially 18 cm/s and which accelerates uniformly through a distance of 55 cm in 4.2 seconds.Vi = 18 cm/s

`ds = 55 cm

`dt = 4.2s

[(vf+vi)/2] * `dt = `ds

[(vf+vi)/2] = `ds/`dt

Vf+vi = 2(`ds/`dt)

Vf = 2(`ds/`dt) –vi

Vf = 2 (55/4.2) – 18

Vf = 8.2 cm/s

(vf – vi) / 4.2 = a

A = 8.2 – 18/4.2

A = -2.3 cm/s^2

Very good solution.

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