Question

i)An aeroplane has a run of 500 m to takeoff from the runway. It starts from restand moves with constant acceleration tocover the runway in 30 sec. What is thevelocity of the aeroplane at the take off?[Ans: 120 km/hr)​

Answer 1

s=500m

u=0 m/s

t=30s

v=?

s=ut+at^2/2

500=0+450a

a=500/450 m/s^2

v=u+at

=0+(500/450×30)

33.33m/s

33.33m/s=(33.33×18/5)km/hr.

=599.94/5 km/hr.

=119.98 km/hr.

or simply by rounding off- 120km/hr.