Question 157280
Remember: {{{Speed=distance/time}}} ---> {{{time=dist/speed}}} ------> eqn 1
{{{distance=speed*time}}} --------------> eqn 2
{{{Train1=T[1]=50m/hr}}}
{{{Train2=T[2]=70m/hr}}}
Note: before T[2] started travelling, T[1] has been running for 1 hour and the total distance travelled: via eqn 2,
{{{(50m/cross(hr))(1cross(hr))=50m}}} -------> eqn3
Now, remember eqn 1: we take the total distance travelled minus eqn 3 (50m). Then we add the speed for both in achieving the distance apart:
{{{time=(350m-50m)/(50m/hr+70m/hr)}}}
{{{time=300cross(m)/(120cross(m)/hr)}}}
{{{time=2.5hrs}}} -----------> it took for {{{T[1]}}} and {{{T[2]}}} when 350 miles apart.
For {{{T[1]}}} -----> {{{2.5hrs}}} + {{{1hr}}}(eqn3) ={{{3.5hrs}}} total time travelling.
Thank you,
Jojo