The table represents the forces on four objects, with directions. Object F1 ↑ F2 → F3 ↠F4 â†" W 30 N 20 N 20 N 30 N X 15 N 35 N 25 N 15 N Y 60 N 0 N 0 N 60 N Z 45 N 0 N 22 N 45 N Which best explains the forces acting on the objects? Objects W and X have balanced forces, and objects Y and Z have unbalanced forces. Objects W and Y have balanced forces, and objects X and Z have unbalanced forces. Objects X and Y have balanced forces, and objects W and Z have unbalanced forces. Objects X and Z have balanced forces, and objects W and Y have unbalanced forces.

Scientists use laser range-finding to measure the distance to the moon with great accuracy. a brief laser pulse is fired at the moon, then the time interval is measured until the "echo" is seen by a telescope. a laser beam spreads out as it travels because it diffracts through a circular exit as it leaves the laser. in order for the reflected light to be bright enough to detect, the laser spot on the moon must be no more than 1.0 km in diameter. staying within this diameter is accomplished by using a special large-diameter laser. part a if λ = 540nm , what is the minimum diameter of the circular opening from which the laser beam emerges? the earth-moon distance is 384,000 km. express your answer to two significant figures and include the appropriate units.

The diagram shows a series of volcanic island and a hot spot determine the direction of movement of the tectonic plate that for the island

Find the magnetic field a distance r from the center of a long wire that has radius a and carries a uniform current per unit area j in the positive z direction.