You are standing at the top of a cliff that has a stairstep configuration. There

Question

You are standing at the top of a cliff that has
a stairstep configuration. There is a vertical
drop of 4 m at your feet, then a horizontal
shelf of 7 m, then another drop of 6 m to the
bottom of the canyon, which has a horizontal
floor. You kick a 0.7 kg rock, giving it an
initial horizontal velocity that barely clears
the shelf below.What initial horizontal velocity v will be
required to barely clear the edge of the shelf
below you? The acceleration of gravity is
9.8 m/s2 . Consider air friction to be negligi-
ble.
Answer in units of m/s

Explanation / Answer

Calculate the time it will take vertically to get to the edge of the shelf by using the formula d = 1/2 at^2, where d = 5m and a = g. That is, 5m = 4.9 m/s^2 times t^2, or t = sqrt(5/4.9). To clear the shelf, use d = vt, or v = 8m divided by the above answer.Round up, in order to clear the shelf. This gives you v=7.92 m/s.

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

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