Answer:
B. 0.1 meters/second/second in the same direction of travel.
Explanation:
Acceleration is the rate of change of velocity. Acceleration is a vector quantity.
a=Îv/Ît
=(vâ-vâ)/(tâ-tâ)
vâ=4 m/s
vâ=6 m/s
tâ=0 s
tâ=20 s
a=(6m/s-4m/s)/(20s-0)
= 0.1 m/s² in the same direction of travel.
Therefore acceleration =0.1 meters/second/second in the same direction of travel.
The acceleration of runner is [tex]\bold{0.1 \ m / s^{2}}[/tex] if his initial velocity is 4 mâs and after 20 seconds the runner's velocity is 6 mâs.
Option: B
From given we came to know that the runner starts his initial velocity is 4 Â , and in 20 s speeds up to 6 mâs, to find acceleration of runner, we know that acceleration is ratio of change in velocity to change in time.
The acceleration is given by the formula:
[tex]\text { Acceleration }=\frac{\text { Change in velocity }}{\text { Change in time }}[/tex]
We know that change in velocity as 4 m/s to 6 m/s and change time as 20 s.
[tex]\Rightarrow \text { Acceleration }=\frac{6-4}{20}[/tex]
[tex]\therefore \text { Acceleration }=0.1 \ \mathrm{m} / \mathrm{s}^{2}[/tex]
Therefore, acceleration of runner will be [tex]0.1 \ m / s^{2}[/tex]
