Answer:
D. 2 m/s²
Step-by-step explanation:
Initial speed of the runner (u) = 6 m/s
Final speed of the runner (v) = 14 m/s
Time taken (t) = 4 s
By using equation of motion, we get:
[tex] \bf \longrightarrow v = u + at \\ \\ \rm \longrightarrow 14 = 6 + 4a \\ \\ \rm \longrightarrow 14 - 6 = 6 - 6 + 4a \\ \\ \rm \longrightarrow 8 = 4a \\ \\ \rm \longrightarrow 4a = 8 \\ \\ \rm \longrightarrow \dfrac{4a}{4} = \dfrac{8}{4} \\ \\ \rm \longrightarrow a = 2 \: m {s}^{ - 2} [/tex]
[tex] \therefore [/tex] Acceleration of the runner (a) = 2 m/s²