Question

An object is thrown straight down from top of a building at a speed of 25m/s it hits the ground with a speed of 40 m/s

1. How high is the building
2. How long was the object in the air​

Answer 1

Answer:

H = 46.75

t = 1.5 sec

Explanation:

we can use newton's equation

s = ut + 1/2 at^2

here s is the height u = 25m/s a = gm/s^2 and t = time

H = 25t + 1/2 gt^2

here final velocity is 40m/s

we have another newton's equation

v = u + at

40 = 25 + 10t

here a = g = 10m/s^2 ( constant all over the earth )

t = 1.5 sec

put value of t in the height equation

H = 37.5 + 11.25

H = 46.75

here in question 2 it is asking for time which we have already find that is t = 1.5 sec

hope it is helpful.............................