Isaac throws an apple straight down from a tree with an initial speed of 5.0 \dfrac{\text m}{\text s}5.0 s m 5, point, 0, start fraction, start text, m, end text, divided by, start text, s, end text, end fraction. It hits the ground with a final speed of 12 \dfrac{\text m}{\text s}12 s m 12, start fraction, start text, m, end text, divided by, start text, s, end text, end fraction. How many seconds did the apple fall?

0.71s

Explanation:

From Newton's law of motion ;

V =U +gt

V is the final velocity or speed

U is the initial velocity or speed

g is acceleration of free fall due to gravity given as 9.8m/S2

Note when a body moves horizontally down its said to do so with the aid of the force of gravity

Hence the final velocity is aided by gravity.

From the above formula;

t =V-U/ g

t= 12-5/ 9.8 = 0.71s

massxgravity x heght=weightxheight= pe

4900=490xh

h=10