Please show all work. Answe to 41 is 30 cm/s, 30 cm/s at 30° below the x axis. A

Question

Please show all work.

Answe to 41 is 30 cm/s, 30 cm/s at 30° below the x axis.
Answer to 42 is 20x10^5 N b) 98 km/s

9.41 T 8.41 [11] .41 I T Two identical balls travelin wo identical balls traveling parallel to the x-axis have speeds of 30 cm/s and are oppositely directed. They collide off center perfectly elastically. After the collision, one ball is moving at an angle of 30° above the +x-axis. Find its speed and the velocity of the other ball. 42I () What minimum thrust ?b f 8.42 (a) What minimum thrust must the engines of a 2.0 × 105 kg rocket have if the rocket is to be able to slowly rise from the Earth when aimed straight upward? (b) If the engines eject gas at the rate of 20 kg/s, how fast must the gaseous exhaust be moving as it leaves the engines? Neglect the small change in the mass of the rocket due to the ejected fuel. [Hint: Study Problem 8.20.] jet gas at the rate of 20o ANSWERS TO SUPPLEMENTARY PROBLEMS

Explanation / Answer

Apply the law of conservation of momentum,

m( V - v ) - m(U + u) = 0

As both have same mass, the masses cancelled out.

V - v - U - u = 0

u = V - v - U.

As collision is elatic, the final velocities V = v,

Therefore, we can conclde that

u = - U

This implies t that whatever the one ball is doing, U, the other one is doing exactly the opposite, - U.

Therefore, the other ball will be going 210o at the same speed U = u.

However, 210o= 30o + 180o

Here 180 + 30 degrees is exactly the opposite direction to 30 deg.

Thus, the speed of the other ball is 30 cm/s at 30° below the x axis.

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

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