A 755-kg two-stage rocket is traveling at a speed of 6.80 times 10^3 m/s away fr

Question

A 755-kg two-stage rocket is traveling at a speed of 6.80 times 10^3 m/s away from Earth when a predesigned explosion separates the rocket into two sections of equal mass that then move with a speed of 2.90 times 10^3 m/s relative to each other along the original line of motion. What is the speed of each section (relative to Earth) after the explosion? Express your answers using three significant figures separated by a comma. What are the direction of each section (relative to Earth) after the explosion? both away from Earth both towards the Earth one away from Earth and the other towards the Earth How much energy was supplied by the explosion? Express your answer to three significant figures and include the appropriate units.

Explanation / Answer

½ * 2.9 * 10^3 = 1.45 * 10^3
Speed of front part relative to the earth =6.8 * 10^3 + 1.45 * 10^3 = 8.25 * 10^3
Speed of rear part relative to the earth = 6.8 * 10^3 – 1.45 * 10^3 = 5.35 * 10^3

b) Since the speed of both parts is positive, both parts are still moving forward.

c)How much energy was supplied by the explosion? [Hint: What is the change in KE as a result of the explosion?]

Initial KE = ½ * 755 * (6.8 * 10^3)^2

KE of front part = ½ * 755 * (6.8 * 10^3)^2
KE of rear part = ½ * 810 * (3.9 * 10^3)^2
Total KE after the explosion = ½ * 755 * (10.7 * 10^3)^2
Increase of KE = ½ * 755 * [(10.7 * 10^3)^2 – (6.8 * 10^3)^2]
The increase of the kinetic energy of each part is approximately 2.576 *10^10 Joules!

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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