A 2.55 kg piece of lead at 40 degree Celsius is placed in a very large quantity of water at 10 degree Celsius and thermal equilibrium is eventually reached. Calculate the entropy change of the lead that occurs during this process. The specific heat of lead is 130 J/(kg K).

The experiment done in lab is repeated, using a ball that has unknown mass m. you plot your data in the form of f 2 versus m/l, with f in rev/s, m in kg, and l in m. your data falls close to a straight line that has slope 3.19 m/(kg · s2). use g = 9.80 m/s2 and calculate the mass m of the ball.

What are the necessary conditions for fusion?

3. which is not a primary color of light? blue red green yellow