A tennis ball of mass 60.0 g is held just above a basketball of mass 586 g. With

Question

A tennis ball of mass 60.0 g is held just above a basketball of mass 586 g. With their centers vertically aligned, both are released from rest at the same moment, to fall through a distance of 1.28 m, as shown in the figure below.

(a) Find the magnitude of the downward velocity with which the basketball reaches the ground. Assume an elastic collision with the ground instantaneously reverses the velocity of the basketball while the tennis ball is still moving down.


(b) Next, the two balls meet in an elastic collision. To what height does the tennis ball rebound?

Explanation / Answer

Since there was no picture, I've assumed the basketball and tennis ball fell the same distance.

(a)

vf2 = vi2 + 2ax where initial velocity is zero, acceleration is gravity (negative) and x is vertical distance.

Solve for vf.

(b)

mbbvbb + mtbvtb = mbbvbb' + mtbvtb'

use final velocity from (a) for the initial velocity of the basketball. The tennis ball will have the same velocity, only negative since it is still moving downward.

Since the collision is elastic, energy is conserved as well...

(.5)mbbvbb2 + (.5)mtbvtb2 = (.5)mbbvbb'2 + (.5)mtbvtb'2

Solve one of those equations for vbb' and plug it in the other to solve.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.