A rocket initially at rest (Vo=0), is fired with a constant acceleration a = 12.

Question

A rocket initially at rest (Vo=0), is fired with a constant acceleration a = 12.0 m/s2. The rocket travels vertically upward for 15.0 s at which time at which time all the fuel is burned, making it a freely falling object. Calculate the maximum height reached by the rocket before falling back to the ground 1045 m 1459 m1942 m 1243 m3003 m 2) A stone is thrown vertically upward with veocity 100 m/s. Calculate the speed of the stone when it has traveled 20% of the expected maximum height 54.8 m/s89.4 m/s77.5 m/s 63.2 m/s70.7 m/s The Space Shuttle travels at a speed of about 7.43 x 103 m/s. The blink of an astronaut's eye lasts about 0.215 s. How many football fields (length- 91.4 m) does the Space Shuttle cover in that time? 12 15 13 10 Due to continental drift, the North American and European continents are drifting apart at an average speed of about 3 cm per year. At this speed, how long (in years) will it take for them to drift apart by another 1250 m? [ year 365 days] 29040 yrs 49967 yrs 33333 yrs 41667 yrs 34667 yrs A sloth moves at a speed of 0.0409 m/s, while the giant tortoise walks at 0.0532 m/s. If both animals start at the same instant how far apart would they be after 14 minutes of walking? 11.8 m 16.2 m 13.3 m 10.3 m 8.9 m

Explanation / Answer

1) E) 3003 m

vertical distance travelled during fuel burned,

h1 = vo*t + (1/2)*ay*t^2

= 0 + (1/2)*12*15^2

= 1350 m

after 15 s, v = vo + a*t

= 0 + 12*15

= 180 m/s

distance travelled after fuel over,

h2 = v^2/(2*g)

= 180^2/(2*9.8)

= 1653 m

so, maximum height = h1 + h2

= 1350 + 1653

= 3003 m

2) B) 89.4 m/s

KEf = 80% of KEi

(1/2)*m*vf^2 = 0.8*(1/2)*m*vi^2

vf = sqrt(0.8)*vi

= sqrt(0.8)*100

= 89.4 m/s

3) B) 17

use, N = v*t/L

= 7.43*10^3*0.215/91.4

= 17

4) D) 41667 years

t = d/v

= 1250/0.03

= 41667 years

5) D) 10.3 m

d = (v2 - v1)*t

= (0.0532 - 0.0409)*14*60

= 10.3 m

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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