1

A student is standing 50 m behind a bus. As soon as the bus begins its motion with acceleration 1 ms^{-2}, the student starts running towards the bus wit a constant velocity u. Assuming the motion to be along a staright road, what is the minimum value of u, so that the student is able to catch the bus?

- 5 ms
^{-1} - 8 ms
^{-1} - 10 ms
^{-1} - 12 ms
^{-1}

0

The bus and the student both start moving.

Suppose at time t, the student catches the bus. Thus, the bus would have covered x distance in that time, and the student is supposed to cover (x+50) distance in the same time t.

The bus covered x distance from initial position,

----(1)

For student,

........................................(2)

substituute eq. (1) from eq. (2)

(since student is moving with const velocity)

t = 10 seconds

Therefore,

u = 10/2 + 50/10

= 5 + 5

= 10 m/s