Question

A bus moving along a straight highway with a speed of 72km/h is brought to rest within a distance of 50m. How long does it take for the bus to stop?​

Answer 1

72km/h=20m/s.

By basic equation of uniform motion,

V² =u² + 2as.

V=final velocity (which is zero in this case).

U=initial velocity (20m/s).

S=50m.

a= -4m/s^2.

Then, by another equation,

V=u+at.

t=5s.

-ve means opposite to motion.