If a spherical convex mirror has a radius of curvature R, the magnitude of its focal length is
A) R/2.
B) R/4.
C) R.
D) 2R.
E) 4R.
A
You might also like to view...
Structure 1 with member BC of length L/2 has force P1 applied at joint C. Structure 2 with member BC of length L has force P2 applied at C. Both structures have constant flexural rigidity EI. The required ratio of the applied forces P1/P2 so that joint B reactions RB1 and RB2 are equal is approximately:
(A) 1
(B) 5/4
(C) 3/2
(D) 2
The Caloris Basin on Mercury covers a large region of the planet, but few smaller craters have formed on top of it. From this we conclude that
A) erosion destroyed the smaller craters that formed on the basin. B) Mercury's atmosphere prevented smaller objects from hitting the surface. C) only very large impactors hit Mercury's surface in the past. D) the Caloris Basin formed toward the end of the solar system's period of heavy bombardment. E) the Caloris Basin was formed by a volcano.
Which statement below regarding the first law of thermodynamics is most correct?
A. A system can do work externally only if its internal energy decreases. B. The internal energy of a system that interacts with its environment must change. C. No matter what other interactions take place, the internal energy must change if a system undergoes a heat transfer. D. The only changes that can occur in the internal energy of a system are those produced by non-mechanical forces. E. The internal energy of a system cannot change if the heat transferred to the system is equal to the work done by the system.
A motor that can do work at the rate of 2 hp has 60% efficiency. How much current does it draw from a 120. V line? (1 hp = 746 W)
What will be an ideal response?