Question

the position of an object moving along the x axis is given by
$x = a + b {t}^{2}$
where a=8.5m, b = 2.5 m/s^2 and t is measured in seconds . what is the velocity at t=0s and t=2.0s? what is the average velocity between t=2.0s and t=4.0s


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Answer 1

Answer:

Explanation:

x = a + bt^2

v = 2bt

Velocity at t = 0 is 0

Velocity at t = 2s is = 2*2.5*2 = 10 m/s

At t = 2s

x = 8.5 + 2.5*2^2

x = 18.5m

At t = 4s

x = 8.5 + 2.5*4^2

x = 48.5m

Average velocity = (48.5 - 18.5) / 2 = 18m/s

Answer 2

ANSWER

x = a + bt²

v = 2bt

velocity at t = 0 = 0

velocity at t = 2s = 2×2.5×2 = 10m/s

At t = 2s

x = 8.5 + 2.5×2²

x = 18.5m

At t = 4 s

x = 8.5 + 2.5×4²

x = 48.5 m

average velocity = 48.5 -18.5 /2

→ 30/2 = 15 m/s