1the earth's crust is made up of plates that can move. which of the following topographic features could be directly formed by the movement of the earth's plates? i. midocean ridges ii. mountains iii. sand dunes iv. coral reefs a. i, ii, and iii only b. ii, iii, and iv only c. i and ii only d. ii and iii only

A10.0 kg cart and a 15kg cart are locked together with a compressed spring between them. they are then released so that the spring pushes the two carts apart. the 10.0 kg cart is moving at 4.5 m/s afterward. how fast is the 15kg cart moving? 3.0 m/s 2.0 m/s 4.5 m/s 5.0 m/s

During the experiment if you could triple the breakaway magnetic force with all other quantities left unchanged, what is the new value for the critical velocity if it was v0 (initial velocity), initially? (b) now if you halved the radius with all other quantities left unchanged, what is the new critical velocity if it was v0 (initial velocity), initially? (c) if during the experiment, critical velocity quadrupled with all other quantities left unchanged, what is the new breakaway force if its magnitude was initially f0,?

If you put a helium-filled balloon in the refrigerator, what will happen?