17) On board the international space station, a bouncy ball is thrown and collid

Question

17) On board the international space station, a bouncy ball is thrown and collides head-on with another bouncy ball of five times the first one's mass. The collision is elastic. (a) What is the ratio of the final velocity of the lighter ball to its initial velocity? (b) What about the ratio of the heavier ball's final velocity to its the lighter ball's initial velocity? Use the first input box for your answer to (a) and the second for your answer to (b) Answer 1 of 2: Answer 2 of 2: Submit All Answers 18) Which combination of statements is most accurate? [Enter your answer as a string of the letter options you believe are correct. For instance, if you think options A, D, and E are correct, then enter "ADE NOTE: There are only 5 tries for this problem.] A) The random jiggling of atoms in a material is an example of source energy B) Source energy can never be purely converted into mechanical energy. C) Macroscopic processes that change source energy don't always increase thermal energy as well D) Mechanical energy can be converted back into source energy, with a corresponding increase in thermal energy E) None of the above Last Answer: ABCD Answer: Incorrect, tries 1/7 Submit All Answers 19) You push a 30 kg crate, accelerating from rest to a speed of 4 m/s. You use up 2500 J of your energy. How energy efficient is this process? Answer: 20) How much thermal energy was generated by your efforts and the sliding friction acting on the crate? Answer: Submit All Answers Submit All Answers

Explanation / Answer

19)Given,

m = 30 kg ; v1 = 0 ; v2 = 4 m/s ; E = 2500 J

We know that

KE = 1/2 m v^2 = 0.5 x 30 x 4^2 = 240 J

we know from the defination of efficiency

eta = Eo/Ei x 100

eta = 240/2500 x 100 = 9.6 %

Hence, eta = 9.6% = 0.096

20)thermal energy lost is:

E(lost) = 2500 - 240 = 2260 J

Hence, E(lost) = 2260 J

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

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