A model rocket is launched straight upward with an initial speed of 60.0 m/s. It

Question

A model rocket is launched straight upward with an initial speed of 60.0 m/s. It accelerates with a constant upward acceleration of 1.00 m/s2 until its engines stop at an altitude of 130 m.
(a) What is the maximum height reached by the rocket?
1264Your answer is incorrect.
Your response differs from the correct answer by more than 10%. Double check your calculations. m

(b) How long after lift-off does the rocket reach its maximum height?
2Your answer is incorrect. s

(c) How long is the rocket in the air?

Explanation / Answer

The rocket accelerated at 1m/s2 for the first 130m. First you need to find the final velocity.

v2 = vo2 + 2ay = 60m/s2 + 2*1m/s2 * 130 so v = 62.13

Now find the time that it is in the air to the top

t = v-vo/g = 0-62.13/9.8 = 6.34s

Now you need to find the final height that it reached in addition the the initial height.

y = yo + vot + 1/2 gt2

y = 130m + 62.13*6.34s + 1/2 * 9.8m/s2 * 6.342

y = 326.92m

b) We already found the time that it stopped accelerating to maximum height, now we just need to find the time that it accelerated for.

t = 62.13-60m/s/1m/s2 = 2.13s + 6.34s = 8.47s

c. total time in the air ... you need to time out how long it took the rocket to fall.

y = 1/2gt2 so t = 2*y/g = 2*326.92/9.8 = 8.17s + 8.47s = 16.64s

Hope that helps

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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