a car moving with a velocity 54km/hour on a straight road by applying brake after covering a distance 20 m compute its acceleration

Question

acceleration

Answer 1

We use the formula

 

a = v/t

 

where:

a = acceleration

v = velocity

t = time

 

We don't know the time. We must find the time.

 

t = d / v

 

t = 20 m / (54000 m / 3600 s)

 

t = 20 m / (15 m/s)

 

t = 1.33 s

 

 

a = (15 m/s) / (1.33 s)

 

a = 11.28 m/s²

 

The breaks are applied, so this slows down the car.  We have a negative acceleration.

 

The acceleration is -11.28 m/s².