Question

A person travelling at 43.2 km/h applies the brake giving a deceleration of 6.0 m/s2 to his scooter. How far will it travel before stopping ?

Answer 1

Acc. To Me,

Answer is 12 m

Given: v=43.2 km/h(see accl. in m/s² so change it to m/s)

43.2*5/18=12 m/s<----velocity in m/s

Accl.=6 m/s²

You see the person at this time travel with initial velocity(u)=12 and after sometime he stop me means final velocity(v)=0

You Find Distance from[--S=ut+1/2at²--]  S=distance ,t=time ,u=initial velocity----1

You have u=12 ,a=-6(minus becz its accl decrease) but you don't know (t)

So find t

v=u + at (v=0,u=12,a=-6,t=find)-------2

0=12 - 6t after solving t=2sec

So you have t=2sec put in -----1

S=12 * 2 - 1/2 * 6 * 2²

S=24-12

S=12m----Answer

I hope you understand the answer