Here we compare two lasers pointers. The green laser emits 1 mW of light power in a beam that is 1 mm in diameter. A red laser emits 2 mW of power in a beam that is 2 mm in diameter. A. Calculate the Intensity of the green laser just after it exits the laser. Express your answer in W/m2.

Apositive rod is placed to the left of sphere a, and the spheres are separated. which best describes the spheres? sphere a is negative and sphere b is positive because protons from sphere a are attracted to the rod and move to sphere b. sphere a is negative and sphere b is positive because electrons from sphere b are attracted to the rod and move to sphere a. sphere a is positive and sphere b is negative because electrons from the rod move to sphere b and protons then move to sphere a. sphere a is positive and sphere b is negative because protons move from sphere b to the rod and also to sphere a.

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

Panel bc in fig. p2.76 is semi-circular, with the 3 meter radius and horizontal straight edge through point b. compute (a) the hydrostatic force of the water on the panel, (b) its center of pressure, and (c) the moment of this force about point b. assume atmospheric pressure on the dry side of the panel