What is the question? I think that you answered it yourself...
Answer:
58.9 N
Explanation:
The wood is buoyed up by the mass of the water is displaces
wood volume = .030 m^3 = 30 000 cm^3
mass of water displaced = 30 000 g = 30 kg
wood mass = 800 kg/m^3 * .030 m^3 = 24 kg
so tension in string = mg = ( 30 kg - 24 kg) * 9.81 m/s^2 = 58.9 N
each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.
How long would it take the space shuttle to go one light-year? The shuttle orbits the Earth at about 5 miles per second (18,000 mph). Light travels at 186,000 miles per second, which is about 37,200 times faster than the shuttle. So the shuttle would need about 37,200 years to go one light-year.
