Question

2.42: A brick is dropped (zero initial speed) from the roof of a
building. The brick strikes the ground in 2.50 s. You may ignore
air resistance, so the brick is in free fall. (a) How tall, in meters, is
the building? (b) What is the magnitude of the brick's velocity jus
before it reaches the ground? (C) Sketch dy-t, Vy-t, and y-t graph
for the motion of the brick.​

Answer 1

(a)We know vf=v0+at

Height of building=0+9.8×2.5=24.5m.