Question

22. Kerry Klutz drops her physics book off her aunt’s high rise balcony. It hits the ground below 1.5 s later.

Answer 1

A). Gravity makes falling objects fall 9.8 m/s faster every second.
After 1.5 seconds, it's falling at (1.5 x 9.8) = 14.7 m/s .

b). The average speed of the physics book is (1/2) (0 + 14.7) = 7.35 m/s .

Falling at an average speed of 7.35 m/s for 1.5 seconds,
the book falls

(1.5 x 7.35) = 11.025 meters 

Answer 2

Answer:

Part (a) v = 14.7 m/s

Part (b) h = 11.025 m

Explanation:

Part (i)

As we know that book is moving under constant acceleration which is due to gravity

so here we know that

$a = 9.8 m/s^2$

$\Delta t = 1.5 s$

$v_i = 0$

so here we will have

$v_f = v_i + at$

$v_f = 0 + (9.8)(1.5)$

$v_f = 14.7 m/s$

Part (b)

height of balcony can be found by another kinematics equation

$\Delta y = v_i t + \frac{1}{2}at^2$

$\Delta y = 0 + \{1}{2}(9.8)(1.5)^2$

$\Delta y = 11.025 m$