Awave of infrared light has a speed of 6m/s and a wave length of 12 m. what is the frequency of this wave? a) 0.5 hz b) 2.p hz c) 18 hz d) 72 hz

Why is alternating current more effective at long–distance travel than direct current? a. the power lines are made out of conductors. b. transformers increase or decrease voltage as needed. c. the ac generator is more efficient. d. ac has lower voltage than dc.

Asolid round steel rod 6.25 mm in diameter and 375 mm long is rigidly bonded to the end of solid square brass rod 25 mm on a side and 300 mm long. the geometric axes of the bare are along the same line. an axial tensile force of 5.4 kn is applied at the extreme ends of the assembly. for steel e = 200 gpa and for brass e = 90 gpa. determine the total elongation for the assembly.

The law of the conservation of momentum says that the total momentum of any closed and isolated system cannot