Question

Mike's car can accelerate from 0 mph to 40 mph in 5 seconds. What is the acceleration of his car in miles per hour per second?

Answer 1

`8 ("mi"/"h")/"s"`

Explanation:

To solve this equation, we can use the kinematics equation

`v_x = v_(0x) + a_xt`

where

• `v_x` is the velocity at time `t` (`40` `"mi/h"`)

• `v_(0x)` is the initial velocity (`0`)

• `a_x` is the acceleration, in `"mi"/("h"-"s")`(miles per hour per second) and

• `t` is the time (`5` `"s"`)

Plugging in known variables, we have

`40` `"mi/h" = 0 + a_x(5` `"s")`

`a_x = color(red)(8 "mi"/("h"-"s")) = color(red)(8("mi"/"h")/"s"`

The acceleration of Mike's car is `8` miles per hour-second (miles per hour per second).