Question

A car traveling west in a straight line on a highway decreases its speed from 30.0 meters per second to 23.0 meters per second in 2.00 seconds. The car's average acceleration during this time interval is
A) 3.5 m/s2 east.
B) 3.5 m/s2 west.
C) 13 m/s2 east.
D) 13 m/s2 west

Answer 1

Answer:

$a=3.5m/sec^2east$

So option (a) is correct option

Explanation:

We have given final speed of the car = 23 m/sec

And initial speed of the car = 30 m/sec

Time in which speed is decreases t = 2 sec

From first equation of motion we know that v = u+at

So acceleration $a=\frac{v-u}{t}=\frac{23-30}{2}=-3.5m/sec^2west$

Negative sign indicate that acceleration will be in opposite direction

So $a=3.5m/sec^2east$

So option (a) is correct option