Question

Initial distance between a girl and bus is 50m. bus starts moving with 1m/s² acceleration. girl starts moving simultaneously with velocity u. what should be minimum velocity of girl to catch bus​

Answer 1

Let the student travels distance s

t

in time t and catches the

bus.

S

1

=ut (1)

Distance travelled by the bus in time t

s

2

=0+

2

1

at

2

.(2)

The student is able to catch the bus if,

s

1

=d+s

2

ut=d+

2

1

×1×t

2

Or, 2ut=2d+t

2

Or, t

2

−2ut+2d=0

Solving the quadratic equation

t=

2

2±

4u

2

−8d

=1±

u

2

−2d

For t to be real

u≥

2d

u≥

2×50

=10m/s.