Question

Consider a block and trolley system as shown in figure. If the coefficient of kinetic friction between the trolley and the surface is 0.04, the acceleration of the system in m/s² is : (Consider that the string is massless and unstretchable and the pulley is also massless and frictionless) :

• A. 3
• B. 4
• C. 2
• D. 1.2

Answer 1

The Correct Option is C

The kinetic frictional force is given by:

\[ f_k = \mu N = 0.04 \times 20g = 8 \, \text{Newton} \]

The net force acting on the system is:

\[ F_{\text{net}} = 60 \, \text{N} - f_k = 60 - 8 = 52 \, \text{N} \]

The total mass of the system is:

\[ m_{\text{total}} = 20 \, \text{kg} + 6 \, \text{kg} = 26 \, \text{kg} \]

The acceleration of the system is:

\[ a = \frac{F_{\text{net}}}{m_{\text{total}}} = \frac{52}{26} = 2 \, \text{ms}^{-2} \]