A 2.3 kg cart is rolling across a frictionless, horizontal track toward a 1.5 kg

Question

A 2.3 kg cart is rolling across a frictionless, horizontal track toward a 1.5 kg cart that is held initially at rest. The carts are loaded with strong magnets that cause them to attract to each other. Thus, the speed of each cart increases. At a certain instant before the carts collide, the first cart's velocity is +4,5 m/s, and the second cart's velocity is -1.9 m/s. What is the total momentum of the system of the two carts at this instant? What was the velocity of the first cart when the second cart was still at rest?

Explanation / Answer

a) The total momentum at this point= momentum of 1st cart + momentum of 2nd cart.
Total momentum = 2.3 x 4.5 + 1.5 x -1.9 = 10.35 - 2.85 = 7.5 kg-m/sec.

b) As magnetic forces are also internal forces there is no external force on the system . Hence momentum is conserved. Initial momentum when only 1st cart is moving is M1xV1 = 2.3V1.

   So, 2.3V1 = 7.5 kg-m/sec =====> V1 = 3.26 m/sec

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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