Question

question 10 of 25
you accidentally drop a book out of the window of a tall building. assuming no air resistance, how fast will the book be moving after 2.8 seconds?
a. 9.8 m/s
b. 3.5 m/s
c. 31.4 m/s
d. 27.4 m/s

Explanation:

Step1: Identify the formula

Use the free - fall velocity formula $v = v_0+gt$. Since the book is dropped, the initial velocity $v_0 = 0\ m/s$, and the acceleration due to gravity $g = 9.8\ m/s^2$, and the time $t = 2.8\ s$.

Step2: Substitute values

Substitute $v_0 = 0\ m/s$, $g = 9.8\ m/s^2$, and $t = 2.8\ s$ into the formula $v=v_0 + gt$. We get $v=0+9.8\times2.8$.

Step3: Calculate the result

$v = 9.8\times2.8=27.44\approx27.4\ m/s$.

Answer:

D. 27.4 m/s