A car goes from 10 to 20 m/s in 4 seconds. How far has it moved in that time?

1 Answer
Jul 17, 2018

Car has moved #60m#.

Explanation:

If initial velocity is #u# and final velocity #v# (at a uniform acceleration) in time #t#,

then acceleration #a# is given by #v=u+at# i.e. #a=(v-u)/t#

and distance is given by #v^2-u^2=2aS#

Here #u=10m/s#, #v=20m/s# and #t=4s#

which gives us #a=(20-10)/4=10/4=5/2m/s^2#

Hence #2xx5/2xxS=20^2-10^2#

or #5S=400-100=300#

i.e. #S=300/5=60m#

Additional information #-# Another important relation is #S=ut+1/2at^2# and here #S=10xx4+1/2xx5/2xx4^2#

= #40+20=60m#