A railroad car of mass m is moving at speed v when it collides with a second railroad car of mass M which is at rest. The two cars lock together instantaneously and move along the track. What is the kinetic energy of the cars immediately after the collision? a. 1/2mv^2
b. 1/2(M + m)(Mv/M)^2
c. 1/2(M+m)(mv/m)^2
d. 1/2(M+m)(mv/(m+M))^2

what best describes physical development during adolescence is the development of secondary sex characteristics happens at a rate unique to each individual.

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.