A 20 g ball of clay travelling east at 2.0 m/s collides with a 30 g ball of clay travelling 30 degrees south of west at 1.0 m/s. What are the speed and direction of the resulting 50 g of clay?

The correct answer is  "c".  it is "c" because melting is an endothermic change, and endothermic get's energy from surroundings. 

The modern-day generator works on the principle of electromagnetic induction discovered by michael faraday in 1831-32. faraday discovered that the above flow of electric charges could be induced by moving an electrical conductor, such as a wire that contains electric charges, in a magnetic field.