Abody a of mass 1.5kg, travelling along the positive x-axis with speed 4.5m/s, collides with another body b of mass 3.2kg which, initially, is at rest. as a result of the collision, a is deflected and moves with a speed 2.1m/s in a direction which is at angle 30° below the x-axis. b is set in motion at an angle θ above the x-axis. calculate the velocity of b after the collision

When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

The force will determine the acceleration.

During physical science, ms. greene challenged her students to produce an energy transformation. james and jill wrapped a 4-inch nail with a coil of fifty turns of wire. they connected one end of the coil to one terminal of a knife switch. they connected the other terminal of the knife switch to the battery. finally, they connected the end of the coil to the other terminal of the battery. james held the tip of a 1-inch nail near the flat end of the 4-inch nail. jill closed the knife switch quickly and then opened it. the 1-inch nail was pulled toward the 4-inch nail. what is the best explanation of why the nail moved? a) electrical energy was converted to mechanical energy in the 1-inch nail. b) the 4-inch nail became an electromagnet and the magnetic force attracted the 1-inch nail. c) the electric current in the 4-inch nail was converted to mechanical energy in the 1-inch nail. d) the 4-inch nail had a positive charge and the 1-inch nail had a negative charge. opposites attracted.