# As she climbs a hill, a cyclist slows down from 25 mi/hr to 6 mi/hr in 10 seconds. What is her deceleration?

##### 2 Answers

19 mi/hr/s

#### Explanation:

Declaration = change in speed/time

So deceleration = (25-6)/10

= 1.9 mi/hr/s

#### Explanation:

*The working for this solution will use SI units.*

First convert the velocities into SI units, then use the appropriate equation of constant acceleration (aka "suvat equation") to calculate the deceleration.

**Convert velocities to kmph**

*mph* to *kmph* .

**Convert velocities to SI ( #ms^(-1)#)**

**Calculate the deceleration**

List the quantities that you know:

Select the appropriate equation:

Substitute values in and calculate deceleration: