19. A ball is dropped from the observation deck of a 350 m tall skyscraper, and

Question

19. A ball is dropped from the observation deck of a 350 m tall skyscraper, and 2 seconds later a second ball is downward. What must the initial velocity of the second ball be if it is to hit the ground at thrown vertically the same time as the first ball? initial velocity of second ball -m/s A point in a regular Cartesian coordinate system is located at x 5.02 meters and y 2.90 meters. Find the point in a polar coordinate system with the same origin that is aligned so that OP is in a direction along the +x axis. R meters 21. A child throws an apple vertically upward with a speed of 13.5 m/s. (a) How high does it go? (b) How long does it take for the apple to reach its highest point? (c) How long does it take to return to its starting elevation after it reaches its highest point? (d) What is the speed of the apple when it returns to the level from which it began? heights meters tl, = seconds t2 seconds speed m/s 22. A 140-N sign is supported by three cables, as shown in the figure below. Find the tension in each of the two cables attached to the horizontal beam. 140 N T1 = N T2=N

Explanation / Answer

here,

19)

for the first ball , h = 350 m

let the time of flight be t

h = 0 + 0.5 * g * t^2

350 = 0 + 0.5 * 9.81 * t^2

solving for t

t = 8.45 s

for the seccond ball

time taken , t' = 8.45 - 2 s = 6.45 s

let the initial speed be u

h = u * t' + 0.5 * g * t'^2

350 = u * 6.45 + 0.5 * 9.81 * 6.45^2

solving for u

u = 22.6 m/s

the initial speed of seccond ball must be 22.6 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.