Answer:
Option D
0.83 m/s2
Explanation:
Time is assumed as 10 seconds
First, convert the speeds from km/h to m/s
20 km/h\times \frac {1000 m}{3600 s}=5.555555556 m/s
\approx 5.56 m/s
50 km/h\times \frac {1000 m}{3600 s}=13.88888889 m/s \approx 13.89 m/s
Acceleration, [tex]a=\frac {v-u}{t}[/tex] where u and v are the initial and final velocities respectively, t is the time taken to accelerate.
Substituting 13.89 m/s for v, 5.56 m/s for u and 10 s for t then
[tex]a=\frac {13.89-5.56}{10}=0.8333333 m/s^{2}\approx 0.83 m/s^{2}[/tex]
