Question

How long does it take a car travelling at 80 m/s to decelerate to 18 m/s with an acceleration rate of -16m/s?

Answer 1

• initial velocity=u=80m/s
• Final velocity=v=18m/s
• Acceleration=a=-16m/s^2
• Time=t

We know

`\boxed{\sf a=(v-u)/(t)}`

`\\ \sf\longmapsto t=(v-u)/(a)`

`\\ \sf\longmapsto t=(18-80)/(-16)`

`\\ \sf\longmapsto t=(-62)/(16)`

`\\ \sf\longmapsto t=3.8s`