Arock is dropped from a height of 2.5 meters. what is it’s velocity when it reaches the ground? 3.5 meters/second

7.0 m/s

Explanation:

The question is on Free-Fall

In a free fall, an object falls freely without only gravity acting on it. Velocity at the top is zero m/s

Height of fall, h=1/2gt²

Velocity, v=gt where g is gravity acceleration=9.8m/s² and t is time taken fall the fall

Finding the t taken for the fall;

h=2.5m but we know h=1/2gt²⇒substitute values in this equation

2.5=1/2×g×t²

2.5=1/2×9.8×t²⇒2.5=4.9t²

make t subject of the equation;

t²=2.5/4.9

t=√2.5/4.9 =0.7143sec

Finding the velocity

v=gt

v=9.8×0.7143=7m/s

the working equation for the angular size is the product of the physical size and 360 degrees divided by the product of two pi and distance from earth. the minimum size would be 0.559 degrees while the maximum size would be 0.49 degrees.