Question

a particle moves in a straight line such that its velocity after t seconds is (2t²-t) m/s. find the distance gone in the first 3 seconds.

Answer 1

22.5 m

Explanation:

Calculate initial velocity (u) when t = 0, and velocity when t = 3:

when t = 0, v = 2(0)² - 0 = 0 ⇒ u = 0

when t = 3, v = 2(3)² - 3 = 15 ⇒ v = 15

SUVAT:

• s = s
• u = 0
• v = 15
• a =
• t = 3

Substituting values into SUVAT formula:

`\sf s=\frac12(u+v)t`

`\implies \sf s=\frac12(0+15)3`

`\implies \sf s=22.5 \ m`