Which of the following would not be useful in trying to correct spherical aberration a. using a combination lens made up of lenses, each of which has a different index of refractionb. using a circular stop to block out the outside rays of lightc. using proper grinding when an object is at a specific distance from the lensd. using a diaphragm to block outside rays of light

Madison pushes with a 210-n horizontal force on a 24-kg crate of coffee resting on a warehouse floor. the force of friction on the crate is 74 n. what is the acceleration?

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.

Abar magnet cut in half will form a total ofpoles.a)fourb)eightc)two