Question

Brad is working on a speed problem in physics class. The problem tells him that a girl runs from her house to the park 0.05 km away in 10 s. Brad calculates that her speed is 0.005 m/s. Is he correct? If not, explain the flaw or flaws in his problem solving process.

Answer 1

Brad is incorrect.

0.05 k m  =  0.05  ⋅  1000 m  =  50 m

s  =  d/ t

where  d  is distance in metres  (m) ,

and t is time in seconds.

and s is speed in meters per second m/s

d  =  50 m   and  t  =  10 s

50m/10s

s = 5 m/s

Brad did most everything correctly just that the number would need to be multiplied by  1000  since the unit  k m  was converted to  m .