Two small objects, with masses m and M. are originally a distance r apart, and the magnitude of the gravitational force on each one is F. Both of the
masses are doubled, and the distance is increased by a factor of 8. What
is the magnitude of the new gravitational force?

(a) assume the equation x = at^3 + bt describes the motion of a particular object, with x having the dimension of length and t having the dimension of time. determine the dimensions of the constants a and b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.) (b) determine the dimensions of the derivative dx/dt = 3at^2 + b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.)

It is really hard for me right know

It is advised not to hold the thermometer by the bulb while reading it