Answer:
Acceleration an automobile is [tex]0.62 m/s^2[/tex].
Explanation:
Acceleration is defined as a rate of change of velocity with respect to to change in time.
[tex]a=\frac{dv}{dt}[/tex]
Given that automobile moving straight in the line changes its speed from 25 km/hr to 70 km.hr in 20 seconds.
Change in velocity = 70 km/hr - 25 km/hr = 45 km/hr
1 km = 1000 m , 1 hour = 3600 seconds
[tex]45 km/hr=\frac{45\times 1000m}{3600s}=12.5 m/s[/tex]
Duration of time = 20 seconds =
Acceleration an automobile:
[tex]a=\frac{12.5 m/s}{20 s}=0.625 m/s^2\approx 0.62 m/s^2[/tex]
