Question

How fast would a girl who rides her bike at 18 m/s for 15 s. Have been traveling if she had covered the same distance in 10 s?

Answer 1

From first equation of motion:

`{ \rm{v = u + at}} \\ { \rm{18 = 0 + (a * 15)}} \\ { \rm{18 = 15a}} \\ \\ { \boxed{ \rm{ \: a = (18)/(15) \: m {s}^( - 2) }}}`

For the second case:

`{ \rm{v = u + at}} \\ { \rm{v = 0 + ( (18)/(15) * 10)}} \\ \\ { \rm{v = 12 \: {ms}^( - 1) }}`