Four cars A, B,C, D of masses 1000kg, 650 kg, 500kg, 2100 kg are running at the same speed of 50 m/s. If all cars are hit from behind with the same force and they continue to move forward, the maximum acceleration will be produced in : 

(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.)

Could we see a galaxy that is 20 billion light-years away?

Calculate the minimum energy required to remove one proton from the nucleus 126c. this is called the proton-removal energy. (hint: find the difference between the mass of a 126c nucleus and the mass of a proton plus the mass of the nucleus formed when a proton is removed from 126c.) express your answer with the appropriate units. emin e m i n = nothing nothing request answer part b how does the proton-removal energy for 126c compare to the binding energy per nucleon for 126c, calculated using eb=(zmh+nmn−azm)c2?