PLEASE HELP ASAP Look at the letter(s) in parenthesis. Are the following units or symbols?

(d) = at2
16 (d)m
1.5 (m)/s
F = (m)a
98 (kg)
Fw = m(g)

An object is 10 cm from the mirror, its height is 1 cm and the focal length is 5 cm. what is the image height? (indicate the object orientation by including the + or - sign with the answer.) hi = cm +1 -1 +10 -10

Consider a double atwood machine constructed as follows: a mass 4m is suspended from a string that passes over a massless pulley on frictionless bearings. the other end of this string supports a second similar pulley, over which passes a second string supporting a mass of 3m at one end and m at the other. using two suitable generalized coordinates, set up the lagrangian and use the lagrange equations to find the acceleration of the mass 4m when the system is released. explain why the top pulley rotates even though it carries equal weights on each side.

Specific heat refers to the amount of heat required to change 1 gram of a substance by degree(s) celsius