1. A ball is thrown vertically upward with an initial velocity of 23 m/s. What a

Question

1. A ball is thrown vertically upward with an initial velocity of 23 m/s. What are its position and velocity after 2 s, after 4 s, and after 8 s?

2.A railroad car starts from rest and coasts freely down an incline.With an average acceleration of 4 ft/s^2, what will be the velocity after 5 s? What distance does it travel? (I cannot figure out the distance part, I got an answer of 20 ft/s^2 for the velocity after 5s)

3. A bullet leaves a 28-in rifle barrel at 2700 ft/s. what were its acceleration and time in the barrel?

Explanation / Answer

1) Vi = 23 m/s Vf = ? S = ? g = -9.8 m/s^2 t = 4sec and t = 8sec If t = 4 sec for Vf we use Vf = Vi +gt Vf = 23 + (-9.8)(4) Vf = -16.2 m/s where -ve sign shows the velocity is decreasing do some mathematics, Similarly do for the t = 8 2) Vi = 0 a = 4ft/s^2 vf = ? Vf = 0 + (4)(5) Vf = 20 m/s

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

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