A car advertisement states that a certain car can accelerate from rest to 70 km/h in 7 seconds. What is the car's average acceleration?

1 Answer
Jan 1, 2016

"average" "acceleration" = 2 7/9 \ "m/s"^2

Explanation:

The acceleration of an object can be calculated based on the formula

a=(v-u)/t

where

  • a= "acceleration"
  • v= "final velocity"
  • u= "initial velocity"
  • t= "time taken"

Here

"70 km/h" = "70 km"/"1 h" * "1 h"/"3600 s" * "1000 m"/"1 km" = 19 4/9 \ "m/s"

From the question

  • u = "0 m/s"
  • v= 19 4/9 \ "m/s"
  • t = "7 s"

So

a = (19 4/9 \ "m/s" - "0 m/s") / "7 s"

a = 2 7/9 \ "m/s"^2