Question 490371
Five minutes after starting from rest, a bike’s velocity is 50 km/hr. What is the bike’s acceleration?

First we change {{{km/hr}} to {{{m/s}}}

{{{expr((50km)/(hr))expr((1hr)/(60min))expr(1min/(60s))expr(1000m/(1km))}}}

Cancel the km's:

{{{expr((50cross(km))/(hr))expr((1hr)/(60min))expr(1min/(60s))expr(1000m/(1cross(km)))}}}

Cancel the hr's

{{{expr((50cross(km))/(cross(hr)))expr((1cross(hr))/(60min))expr(1min/(60s))expr(1000m/(1cross(km)))}}}

Cancel the min's

{{{expr((50cross(km))/(cross(hr)))expr((1cross(hr))/(60cross(min)))expr(1cross(min)/(60s))expr(1000m/(1cross(km)))}}}

All that's left is

{{{expr((50*1000m)/(60*60s))}}}

{{{expr((50000m)/(3600s))}}}

{{{expr((500m)/(36s))}}}

{{{expr((125m)/(9s))}}}

{{{a = (v[f]-v[0])/t}}}

{{{a = (expr(125m/(9s))-expr(0m/s))/(5s)}}}

{{{a = (expr(125m/(9s)))/(5s))}}}

{{{a = expr(125m/9s)*expr(1/(5s)))}}}

{{{a = 125m/(45s^2)}}}

{{{a=expr(125/45)expr(m/s^2)}}}

{{{a=expr(25/9)expr(m/s^2)}}}

{{{a=2.778expr(m/s^2)}}}