Physics

posted by .

Am I correct?

Two carts have a compressed spring between them and are initially at rest. One of the carts has total mass, including its contents, of 5.0 kg, and the other has total mass of 3.0 kg. If the 3.0 kg cart is moving at 3.0 m/s after the spring is allowed to push the carts apart, what is the velocity of the 5.0 kg cart after release? The system is closed.
(Points : 1)
-1.8 m/s <-------

-5.0 m/s

-0.56 m/s

-0.0 m/s

A car traveling north at 10.0 m/s crashes into a car traveling east at 15 m/s at an unexpectedly icy intersection. The cars lock together as they skid on the ice. The two cars have the same mass. What is their combined speed after the collision? (Points : 1)
5.0 m/s
15 m/s
9 m/s <-------
25 m/s

  • Physics -

    Once again, it is true again and again:

    Momentum before = momentum after if no EXTERNAL force on system, like here:

    0 = 5 v + 3 * 3

    v = -9/5 = -1.8

  • Physics -

    north momentum = 10 m
    east momentum = 15 m

    final mass = 2 m

    final north v = 10 m/2 m = 5 m/s
    final east v = 15 m/2 m = 7.5 m/s

    |v| = sqrt(25+56.25) = 9.1 so yes

  • Physics -

    OK, thank you, I understand :)

  • Physics -

    Good, you are welcome :)

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    A 1.o kg cart A and 2.0 kg cart B are at rest on a frictionless table. A cord and a spring of negligible mass join the two carts. The spring is compressed 0.060m between the two carts until the spring's potential energy is 12 Joules. …
  2. physics

    two air carts of mass m1=0.84kg and m2=0.42kg are placed on a frictionless track. cart1 is at rest and has a spring bumper of constant force F=690N/m.cart2 has a metal bumper and moves towards cart1 with a speed V=0.68m/s. A) what …
  3. physics

    The drawing below shows two laboratory carts (each has a mass of 1.0 kg) X and Y in contact with a compressed exploder spring between them. The mass on cart Y is 2.33 kg, distance A is 6 cm, distance B is 9 cm. What mass must be placed …
  4. Physics

    I know I said I didn't know how to start my last question and them figured it out on my own but this one I have tried to work out and really can't get. We have two carts that have magnets to keep them from touching. One cart is initially …
  5. Physics please help!

    I have tried to work this one out and really can't get it. We have two carts that have magnets to keep them from touching. One cart is initially at rest and we push the second cart towards it. Because the two carts will not actually …
  6. Physics

    I think I chose the correct answer. In a closed system, two carts have a compressed spring between them. One of the carts has a total mass, including its contents, of 2.0 kg, and the other has total mass of 1.0 kg. Which cart experiences …
  7. Physics

    As shown in the figure below, we have three air carts (labeled #1, #2, and #3) on an air track. The carts are equipped with spring bumpers so that all collisions are elastic. The masses of the carts are m1 = 5m, m2 = 2m, and m3 = m. …
  8. Physics

    W have three air carts (labeled #1, #2, and #3) on an air track. The carts are equipped with spring bumpers so that all collisions are elastic. The masses of the carts are m1 = 5m, m2 = 2m, and m3 = m. Initially, cart #1 is given a …
  9. physics

    A 2.9-kg cart is rolling along a frictionless, horizontal track towards a 1.5-kg cart that is held initially at rest. The carts are loaded with strong magnets that cause them to attract one another. Thus, the speed of each cart increases. …
  10. Physics

    Two carts with the same mass are pushed together with a compressed spring between them. When the carts are let go, both move apart, from the spring force. Which will move with a higher speed?

More Similar Questions