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

Answer:

#"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#