13-17. A brass ball i 20.0 m/s. One second later, the ball has an instantaneous

Question

13-17. A brass ball i 20.0 m/s. One second later, the ball has an instantaneous velocity in the upward direction of 15.0 m/s. s shot vertically upward from the surface of an atmosphere-free planet with an initial speed of 13. What is the magnitude of the acceleration due to gravity on the surface of this planet? A) 5.0 m/s B) 9.8 m/s C) 12 m/s D) 15 m/s E) 24 m/s 14. How long does it take the ball to reach its maximum height? A) 2.0s B) 2.3s C) 4.0s D) 4.6s E) 80s 15. How high does the ball rise? A) 70.0 m B) 10.0 m C) 50.0 m D) 20.0 m E) 40.0 m 16. Determine the velocity of the ball when it returns to its original position. Note: assume the upward direction s positive. A) +20 m/s B) -20 mys C) +40 m/s D) -40 m/s E) zero m/s 17. How long is the ball in the air when it returns to its original position? A) 4.0s B) 4.6s C) 8.0s D) 9.2s E) 16s 18. In a race, Marcos runs 1.00 mile in 4.02 min, mounts a bicycle, and rides back to his starting point, which is also the finish line, in 3.02 min. What is the magnitude of Marcos' average velocity for the race? A) zero mi/)h B) 12.1 mi/h C) 14.9 mi/h D) 17.0 mi/h E) 19.9 mi/h

Explanation / Answer

13) accelaration is a = (V-Vo)/t = (15-20)/1 = -5 m/s^2

so the answer is A) 5 m/s^2

14) t = Vo/a = 20/5 = 4 sec

15) Hmax = Vo^2/(2*a) = 20^2/(2*5) = 40 m

16) it reaches with the same speed but direction is downwards

hence the answer is -20 m/s

17) time of flight is T = 2*vo/a = 2*20/5 = 8 sec

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

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