Question

A beaker of mass M_B, containing volume V of pure water, is at rest on a horizontal scale in a lab. A block of aluminum metal, mass m_Al, is hanging from a spring scale and is completely immersed in the water. (a) [10 pts] Draw a fbd of the metal block, and write Newton’s second law, putting in all your forces. (You will need to look up “buoyant force” in Chapter 14, which we skipped.) Draw a fbd of the [beaker+water] system and write Newton’s second law, putting in all your forces. Name any third-law pairs. (b) [5 pts] Find the readings of both scales if M_B = 0.2 kg, V = 0.3 l, and m_AL = 0.1 kg. (c) [5 pts] If the water was originally at 0°C (before the metal was lowered in) and the metal at 20°C, find the final temperature of the system, neglecting any heat flow to or from the beaker or lab.

Answer 1