Explanation:
Given:
Final speed of mass A = Va
Final speed of mass B = Vb
Mass of A = Ma
Mass of B = Mb
Ma = 2 × Mb
By conservation of linear momentum,
0 = Ma × Va + Mb × Vb
0 = 2 × Mb × Va + Mb × Vb
Vb = - 2 × Va
Energy of the spring, U = 1/2 × k × x^2
1/2 k x² = 1/2 × Ma × Va² + 1/2 × Mb × Vb²
35 = 1/2 × Ma × Va² + 1/2 × Mb × Vb²
Ma × Va² + Mb × Vb² = 70
2 × Mb (-Vb/2)² + Mb × Vb² = 70
1/2 × Mb × Vb² + Mb × Vb² = 70
3/2 × Mb × Vb² = 70
Mb × Vb² = 140/3
= 46.7 J
Ma = 2 × Mb and Vb = - 2 × Va
Ma/2 × (4 × Va²) = 140/3
Ma × Va² = 70/3
Kinetic energy of mass A, KEa = 1/2 × Ma × Va² = 23.3 J
Kinetic energy of mass B = 1/2 × Mb × Vb² = 46.7 J
Chemical properties are based on the ability or inability of the substance to produce new substances. Copper's malleability, color, luster, and thermal and electrical conductivity are contrasted with its ability to react with concentrated nitric acid and silver nitrate. Copper has a melting point of 1083.4 +/- 0.2°C, boiling point of 2567°C, specific gravity of 8.96 (20°C)
so its D
question answered by
(jacemorris04)
The correct answer is C) frequency.
In fact, the frequency is the number of wave crests (or pulses) per seconds. In our problem, the machine that produces the wave pulses two times per second, so this is exactly the frequency of the compression wave.
Last month, we featured IRB best practices (“IRBs: Navigating the Maze” November 2007 Observer), and got the ball rolling with strategies and tips that psychological scientists have found to work. Here, we continue the dissemination effort with the second of three articles by researchers who share their experiences with getting their research through IRB hoops. Jerry Burger from Santa Clara University managed to do the seemingly impossible — he conducted a partial replication of the infamous Milgram experiment. Read on for valuable advice, and look for similar coverage in upcoming Observers. These are the first words I said to Muriel Pearson, producer for ABC News’ Primetime, when she approached me with the idea of replicating Stanley Milgram’s famous obedience studies. Milgram’s work was conducted in the early 1960s before the current system of professional guidelines and IRBs was in place. It is often held up as the prototypic example of why we need policies to protect the welfare of research participants. Milgram’s participants were placed in an emotionally excruciating situation in which an experimenter instructed them to continue administering electric shocks to another individual despite hearing that person’s agonizing screams of protest. The studies ignited a debate about the ethical treatment of participants. And the research became, as I often told my students, the study that can never be replicated. Hope this helps!
