A Block of Mass M_b Rests on a Horizontal Surface

question 4

Multiple Choice

A block of mass m_b rests on a horizontal surface and is accelerated by means of a horizontal cord that passes over a frictionless peg to a hanging weight of mass m_w.The coefficient of kinetic friction between the block and the horizontal surface is µ and the tension in the cord is T.The acceleration of the block is given by

• A)(T - m_wg)/(m_w + m_b)
• B)T/(µm_bg + m_b)
• C)(T - µm_b)/m_b
• D)(m_wg - T)/m_w
• E)T/m_b - µm_bg

---

Definitions:

Receptor Molecules

Proteins located on the cell surface or within cells that bind specific substances, triggering a biological response.

Up-regulation

refers to the process of increasing the response to a stimulus, often involving an increase in the number of receptors on a cell's surface.

Receptor Sites

Specific locations on cell surfaces or within cells where molecules, such as hormones or neurotransmitters, bind to elicit a response.

Membrane-bound Receptor Model

A theory describing how specific proteins located on the cell membrane bind to external molecules, triggering a response inside the cell.