---

Consider a grey squirrel falling out of a tree to the ground.

(a) If we ignore air resistance in this case (only for the sake of this problem), determine a squirrel’s velocity just before hitting the ground, assuming it fell from a height of 3.0 m.

(b) If the squirrel stops in a distance of 2.0 cm through bending its limbs, compare its deceleration with that of the airman in the previous problem.

---

Solution:

Part A

We are given the following: $v_0=0 \ \text{m/s}$; $a=-9.80 \ \text{m/s}^2$; and $\Delta x=-3.0\ \text{m}$.

Note that the acceleration is due to gravity and its value is constant at $a=-9.80 \ \text{m/s}^2$. Also, the distance $x$, is negative because of the direction of motion. For free-fall, downward motion is considered negative. To solve for the velocity just before it hits the ground, we will solve $v_f$in the formula

Substituting the given values:

Part B

We are given the following: $v_f=0 \ \text{m/s}$; $v_0=7.7 \ \text{m/s}$; and $\Delta x=0.02 \ \text{m}$

To solve for the acceleration we shall use the same formula as that in Part A. Solving for the acceleration $a$:

Substituting the given values:

This is approximately 3 times the deceleration of the airman from the previous problem, who was falling from thousands of meters high.

---