You and your friends are on vacation in Hawaii and see a fire dancer at a Iuau.

Question

You and your friends are on vacation in Hawaii and see a fire dancer at a Iuau. He makes circles with a ball on a string that is 25cm long. You count the amount of rotations the fireball makes count it to be 4 times every second. Find the speed and acceleration of the fireball. The dancer accidentally lets go of the string and the ball shoots into the air straight at you with an angle of 35 degrees to the ground. Assume when the ball is let go it is 1.5 m from the ground. You are standing 6 m away from the fireball. Does it hit you and make you catch on fire? Why or why not? What is the speed of the ball when it hits the ground?

Explanation / Answer

a) speed = 2 x 3.14 x 0.25 x 4 m/s = 6.28 m/s

accelaration = (6.28)2/0.25 = 157.75 m/s2

b) time to hit ground ,

1.5 = -6.28sin35 x t + 0.5 x 9.8 x t2

t = 1.03 s

horizontal distance = t x 6.28cos35 = 5.3 m < 6 m

so ball will not hit

c) speed = sqrt[{6.28sin35 - 9.8(1.03)}2 + (6.28cos35)2] = 8.29 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.