Vision Problems: A person is nearsighted with a far point of 75.0 cm.(a) What focal length contact lens is needed to give him normal vision?(b) What is the power of the corrective lens?
What will be an ideal response?
(a) -75.0 cm (b) -1.33 diopters
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A wind farm generator uses a two-bladed propeller (see figure) mounted on a pylon at a height of 20 m
The length of each propeller blade is 12 m. A small piece from the tip of the propeller breaks off when the propeller is vertical. At that instant, the period of the motion of the propeller is 1.2 s. The fragment flies off horizontally, falls with negligible air resistance, and strikes the ground at P. (a) How far is point P from the base of the pylon? (b) At what angle with respect to the vertical is the fragment moving just as it strikes the ground at P? What will be an ideal response?
You and I are emitting primarily
A) X-ray radiation. B) infrared radiation. C) visual radiation. D) radio radiation.
Pressure in a Liquid: A container has a vertical tube, whose inner radius is 12.00 mm, connected to it at its side, as shown in the figure. An unknown liquid reaches level A in the container and level B in the tube-level A being 5.0 cm higher than level B. The liquid supports a 20-cm high column of oil, between levels B and C, whose density is 320 kg/m3. The gauge pressure at level B is closest to
A. 630 Pa. B. 310 Pa. C. 470 Pa. D. 790 Pa. E. 940 Pa.
Charge of uniform density (20 nC/m2) is distributed over a cylindrical surface (radius = 1.0 cm), and a second coaxial surface (radius = 3.0 cm) carries a uniform charge density of ?12 nC/m2. Determine the magnitude of the electric field at a point 2.0 cm from the symmetry axis of the two surfaces.
A. 2.3 kN/C B. 1.1 kN/C C. 1.7 kN/C D. 3.4 kN/C E. 4.5 kN/C