Question

QUESTION 4 An automobile traveling on a straight, level road at 25 km/hr speeds up to 70 km/hr in 20s. What was the magnitude of the auto's acceleration, in meters per second squared? 62m/sA2 6.2m/s 2 O62m/s 2 062m/sA2

Answer 1

Answer:

Acceleration an automobile is $0.62 m/s^2$.

Explanation:

Acceleration is defined as a rate of change of velocity with respect to to change in time.

$a=\frac{dv}{dt}$

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

$45 km/hr=\frac{45\times 1000m}{3600s}=12.5 m/s$

Duration of time = 20 seconds =

Acceleration an automobile:

$a=\frac{12.5 m/s}{20 s}=0.625 m/s^2\approx 0.62 m/s^2$