Question

Imagine a rock is dropped from the top of a tall building. After 2 seconds of falling, the rock’s instantaneous speed is approximately 20m/s. does anyone know is it true or false

Answer 1

Answer:

TRUE

Explanation:

As we know that stone is falling freely from rest

so here we can use kinematics to find the final speed of the stone

$v_f = v_i + at$

here we know that

$v_i = 0$

$a = 9.81 m/s^2$

$t = 2 s$

now we have

$v_f = 0 + (9.81)(2)$

$v_f = 19.62 m/s$

so final speed of the rock is nearly 20 m/s

Answer 2

True
It's in free fall( 9.8 m/s), 2 seconds have passed.