Block a of Mass 5

question 20

Multiple Choice

Block A of mass 5.0 kg and block X are attached to a rope which passes over a pulley, as shown in the figure. An 80-N force P is applied horizontally to block A, keeping it in contact with a rough vertical face. The coefficients of static and kinetic friction between the wall and block A are μ_s = 0.40 and μ_k = 0.30. The pulley is light and frictionless. The mass of block X is adjusted until block A moves upward with an acceleration of 1.6 m/s². What is the mass of block X?

• A) 9.9 kg
• B) 9.3 kg
• C) 8.7 kg
• D) 8.1 kg
• E) 7.5 kg

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Definitions:

Terminals

The end points of an electrical device or a cable where connections are made to enable the flow of electrical current.

Diode

A semiconductor device that allows current to flow in one direction only, used in electronics for rectification and signaling.

Relay

Any of a number of devices that receives a signal and then effects an action. In vehicle electrical circuits, relays are used to allow a small current circuit to control a large current circuit such as in a starter relay. Also known as a pilot.

Transistor

A semiconductor device used to amplify or switch electronic signals and electrical power, fundamental in modern electronic circuits.