Question

question 5 of 10
a raccoon falls out of a tree from a height of 1.2 m. which equation can you use to calculate the time it takes the raccoon to fall to the ground? (assume no air resistance.)
a. $v_{2}^{2}=v_{1}^{2}+2adelta d$
b. $a = \frac{delta v}{delta t}$
c. $delta d=\frac{1}{2}adelta t^{2}+v_{1}delta t$
d. $v_{2}=sqrt{2adelta d}$

Explanation:

Step1: Identify the known - unknowns

The raccoon starts from rest ($v_1 = 0$), the acceleration $a = g= 9.8\ m/s^{2}$ (acceleration due to gravity), the displacement $\Delta d=1.2\ m$, and we want to find the time $\Delta t$.

Step2: Select the appropriate kinematic equation

The kinematic equation $\Delta d=\frac{1}{2}a\Delta t^{2}+v_1\Delta t$ is suitable. Since $v_1 = 0$, it simplifies to $\Delta d=\frac{1}{2}a\Delta t^{2}$. This equation allows us to solve for $\Delta t$ when we know $\Delta d$ and $a$.

Answer:

C. $\Delta d=\frac{1}{2}a\Delta t^{2}+v_1\Delta t$